Q:

DFRPG city creation via telepresence

I'm planning a DFRPG campaign for the first time since my group began gathering via telepresence.  How can we best approximate sitting around the table to collaborate, talk, and work on city creation1 over a commonly shared map? 
Here's what I expect we'll need to do:

Draw a map of key landmarks and their relationship to each other.  Each side needs to be able to point at/draw on it so that everyone else can see them add/remove features. 
Label and write details about each landmark. 
Designate and describe characters as the "face" of various locations. 

Here's what we currently have:
Half the group is in my living room, the other half is in a friend's room in another country.  We typically connect the two rooms using Skype for voice and face/body language, and a Google document for shared editing of active game info (I've got it hooked up to a smallish TV, the other side is using a biggish monitor).  Our games don't use grids and minis, so this works well most of the time. 
We're using Windows PCs on both ends for the Skype + GDoc interface.  My side has access to a Mac laptop and an Android tablet, while the other side has a Windows tablet.  Both sides also have drawing tablets, which may make some solutions more graceful to implement. 
Given our setup, I can't easily show "the other side" the map in real-time, and they can't add to it themselves.  How have you solved this problem in your games?2

1 If you need a refresher on DFRPG city creation, it's summarised about halfway down this page, and more detail is given in the "City Creation" links here. 
2 I'm told Roll20 is a good tool for this sort of thing, but all the unrelated fiddly bits obscured how to use it just for my purpose--so if the answer is "use X app/service," I'd appreciate pointers on how to make that happen. 

A:

Stick With Google
Since you're already using Google Docs to keep your campaign info I'd suggest you stick with the Google ecosystem.  One of the hidden gems in Google Drive is Google Drawings.  Just like other GDocs, you can set  permissions for others to edit them, and it's all updated in real-time (like other GDocs). 
While you can't access it via doc.google.com, if you go to drive.google.com, you can:

Google Drawings has all the tools for a representative map (since you're playing DFRPG, I'm assuming you don't need a super-detailed map1 for your city).  You can add shapes, lines, text boxes2, import images, and free-draw in real-time with your friends. 
Your Requirements

Draw a map of key landmarks and their relationship to each other.  Each side needs to be able to point at/draw on it so that everyone else can see them add/remove features. 

GDocs is all about the collaboration, as you know from working with their text editor.  GDrawings' line, shape, and text box options cover what you are asking for. 

Label and write details about each landmark. 

As mentioned above, you can add shapes for landmarks—or import an existing image you have to represent the landmark.  Using text boxes, you can add basic descriptions to them, and reference them in your master G(text)Doc for more details. 

Designate and describe characters as the "face" of various locations. 

With the shapes and arrows (found in the lines option) you can show relationships between places, faces, and PCs\$^3\$.
My Experience
When I did this a few years ago, we all were on a Google Hangout for communication, and used it as a "writer's room".  Just like if we were at the same physical table, we threw ideas back and forth, and when something stuck with the group, I added it to the map. 
Of course, I was the designated map-adder because I was the GM and the most familiar with the software.  Since you have a tablet at each end of the conversation, you can easily use those to pass around if people want to add their own things to the map, or just have one designated mapper in each location.  Either way, this would free up the biggest monitor/TV screen for the video chat, and give the idea of "passing around the map" if y'all were in the same location. 

\$^1\$If you do want a super-detailed map, you can always use Photoshop, GIMP, Inkscape, etc and import the map as your background in GDrawings.  Then anything added will be superimposed on top of the map
\$^2\$Note that you can double-click on a shape to add text directly to the shape, you do not need to add a separate text box
\$^3\$I'm a fan of the Smallville RPG system of using squares to represent PCs, circles to represent NPCs, and diamonds to represent locations

A:

Draw straight onto the map! 
Using Google My Maps, you can create your own map overlays over any place on Google Maps, draw onto it with simple lines and polygons, and add markers for locations as needed. 
Each of the features (markers, lines and polygons) added to the map can be given a label and a description, which everyone with map access will be able to see, and colour-coded as needed.  Images and videos can be added to each feature as well. 
This is just a tool for creating the map together - you will need another way of communicating with your players to discuss the creation, such as Skype. 
Requirements

Draw a map of key landmarks and their relationship to each other.  Each side needs to be able to point at/draw on it so that everyone else can see them add/remove features. 

Google Maps will provide the backdrop, so you can use anywhere that is a real place.  Markers can be added by selecting "add marker" and clicking where to place it; clicking-and-dragging moves it.  Lines and polygons can be drawn, and is as simple as selecting "draw a line" and clicking each vertex of the line or polygon (click the first point again to join up into a polygon); extra vertices can be added a and existing ones moved. 

Label and write details about each landmark. 

Each feature added to the map allows you to add labels and descriptions to it to describe it. 

Designate and describe characters as the "face" of various locations. 

Each marker on the map can use one of five different icons - so character markers can be a separate shape to the location markers. 
Drawbacks
The majorly significant drawback is that unlike many other Google collaboration products, edits made to the maps are not synced across to other users in real-time - the map will need to be reloaded.  This could possibly make this solution unworkable, depending on the rapidity of which changes are being made to the map between remote users.  However, it should still be able to give both sides reference points with relative ease. 
Other benefits
My Maps allows you to use multiple layers which can help with organisation of the different features.  Each layer can be toggled on or off to show or hide the items in that layer.  So you might, for instance, decide that you will have three layers, one for locations, one for faces, and one for neighbourhoods; or you may decide to have each neighbourhood as a separate layer.  My Maps allows you to drag and drop the different items between layers, so it is possible to reorganise later if necessary. 
All features can also be colour-coded as one of thirty colours.  It may be useful to use specific colours to identify features that belong to the same faction, or colour-code them by neighbourhood. 
Accessibility
Google My Maps can be accessed from any browser - including several mobile browsers (I have tried it on Chrome mobile and it feels just like in the PC browser), so it should be accessible from at least the Android tablet.  Google claims that it works on Safari, but I'm not sure about Windows mobile. 
Google do provide a Google My Maps app for Android tablets, but I really can't recommend it - it only seems to allow you to place markers (not draw lines and polygons), and is generally a lot more clunky than the mobile browser experience! 

A:

Given our setup, I can't easily show "the other side" the map in
  real-time, and they can't add to it themselves.  How have you solved
  this problem in your games? 

I didn't, because I never had that problem when I used tele-presence for DFRPG.  Maps are not crucial to the Fate experience nor even the specific Dresden iteration where locations are written out.  That's because things like distance is handle extremely abstractly, via zones, which can be as large or as small as you need them to be for the scene.  You can create locations without any sense of geography for the city, because when you use them the only way they interact is travel between them, which Fate is designed to handle as abstraction.  
When you are in the location, Sweet Ass Landmark it doesn't matter if Bad Guy's Manor is 20 miles Northwest or 5 due south.  The general direction doesn't even matter, until its important for the story.  Think of everything along the Heisenberg Principle.  Until it's observed it could be anywhere(or anything).  This is exceptional for Fate and Dresden in particular because when it does become important you can handle it via aspects.  Perhaps you compel someone's Just My Luck Trouble to make is so right when the need to get somewhere, turns out it's across town and there is no clear route to get there.  Or alternatively, once the group figures out the need to go somewhere an enterprising players wants to make a declaration that it's close by and they know a super fast route.  Sweet, you've got them engaged. 
In Dresden the players help create the world, not just at the beginning but the whole time through.  The more details you nail down at the beginning the less play space you leave them for cool things to come up with later.  In addition those details may never get used or become important.  That's wasted effort and narrative focus.  Much like in a written story, in Fate you really only want to put wants going to come up, what's important to the story in your exposition.  It's that narrative focused.  Give people enough to know what's going on and what they have to work with and let the rest come out during emergent play. 
One of the main reasons I stress this is I've often lost groups during world creation and that was a much worse problem when done online.  World building can tend tedious for alot of players after awhile.  Adding the necessity of mapping everything out in relation to each other will add to the time and the to task list of things they are doing that aren't "playing the game".  Obviously if your entire group enjoys mapping things that's less of an issue but I've never seen that to be the case. 
When pitching locations to the group we rarely ever bothered with geolocation, except to put maybe the down the most general of notes like, this location is in a ghetto or it's near the lake.  My players never ran into issues with not knowing where stuff was.  They simply asked when they needed to know and between us we could come up with the thing that fit best, whether through GM fiat or through use of the mechanics.  
So in conclusion if the map looks like it will add any bit of frustration to the process, don't use it, because it doesn't add much and what it does add actually removes from potential enjoyable gameplay later.