[Galaxy S III General (US Carriers)] 1buprofen:
I wrote this guide for those of you, like myself, that are new to using Dropbox. Since T-Mobile and Sprint are offering 50GB free for two years I decided to try it out. So far I've been very impressed with it. Hopefully this guide will help you maximize your Dropbox experience.

Setting up your Dropbox account:

During the initial phone setup there is a screen showing the 50 GB free offer. I signed up at this time. (If anyone can confirm if you can get back to this screen later please let me know and I'll add it back to the guide. I assume you can get back to it by going back into Dropbox on your phone if you haven't sign up yet but I wont be able to test this unless I reset my phone which I wont be able to do until next week because I have family in town for my son's first Bday and don't have time to re-setup everything yet. )

If you already have a Dropbox account log in from the phones offer screen using your current account. If you don't have an account yet you can make an account on your phone, but I would advise making one ahead of time on a computer to take advantage of an extra 500MB from a referral. If you have a friend that uses Dropbox ask them for their referral link. They will gladly give you this because they (and you) will get an extra 500MB for the referral. You just click the link they provide and provide a name, email address, and a password. Then after the account is setup, use that login information on your phone. If you don't have any friends that use Dropbox yet, feel free to use my referral link for the extra 500MB (http://db.tt/Msdz5Yxe)

When you login to your account you will not see the 50GB yet. Don't be alarmed. You will receive an email explaining that you need to do the "Get Started" guide once you do five of the seven steps in "Get Started" you will be awarded your 50GB. These steps are easy things like complete the Dropbox walkthrough, install Dropbox on another computer, upload files to Dropbox, etc. They walk you through all of the steps.

How to get more storage for free:

If you want more free storage there are a few things you can do:

Upload files from your phone camera or other USB device - You get up to 3GB of free space by uploading pictures to drop box. 500MB increments until you've uploaded 3GB. Sounds like you can get 3GB from Phone upload and another 3GB from uploads from computer client but I've only been able to get 3GB total. If anyone else can confirm this please let me know.

Refer friends - you get 500 MB (and so do your referrals) for each person you refer, up to 16GB

"Get Free Space!" - You'll notice a get free space link at the top right of the Web interface there are all sorts of little things you can do to get more space like write a comment to Dropbox and connecting your Twitter or Facebook account with Dropbox.

Scavenger hunts - Periodically DropBox will do scavenger hunts were you can get free storage for participating. The most recent scavenger hunt is closed, but here is a link showing some info about what it is http://blog.dropbox.com/?p=1194

It's not free, but you can also pay for more storage if you need more.

Security:

If you are security conscious you can encrypt your data before you put it on Dropbox. Truecrypt works well for PCs. I'm researching options for android and will add that info here.

I have not tried this yet but I'm going to try to use Cryptonite to see how well it works

http://code.google.com/p/cryptonite/

Other Tips:

I plan on putting my KeePass database in Dropbox so that I have my passwords everywhere. There is an Android implementation of Keepass on Google play

If you have any other tips for Dropbox please let me know and I'll add them here.

NOTE: Keep in mind this 50 free GB is a 2 year promo by Dropbox and Samsung and at the end of the 2 years you will need to purchase storage from Dropbox or move your data elsewhere. Still pretty cool for 2 years though. You will get to keep 2GB of the 50 for free plus any of the free space you earned using the techniques above.