Scenario

I'm going to be in a public area taking portraits of many people (for example, at a themed, public event, or while doing a 100 Strangers Project, etc..)

After taking someone's portrait, I want them to give them access to their portrait (and only theirs, not everyone else's).

So, given all the pictures I take that day, how can I keep track of all the photos (matching up them up with their portrait, and then providing them a way to see/share the photo)? Also, what token, if any, could I give them to find or receive their photo later on?

Requirements

The ideal solution for me would


give them access to only their portrait
minimize the amount of personal information I get from them at the time of encounter (a name only, for example. The assumption is that people would not want to give out their contact information.)
minimize wasting their time (in other words, be a socially elegant solution)
maximize the amount of time I spend shooting while I'm out "in the field" as opposed to bookkeeping


I'm comfortable giving them my contact information.


Question: Does scratched Teflon coated frying pans contain carcinogens which can cause cancer?
Answer: Teflon is a polymer of perfluorooctanoic acid (PFOA) and related compounds.  PFOA is thought to be a carcinogen.  

I think there's an urban legend that if you really heat teflon up or burn it (it doesn't burn as flouroxides are not stable in air) that you might get some of the constituent chemicals out into the air.  

Once the flourocarbons are polymerized into fibers and surface coated a metal pan, they are chemically inert and aren't carcinogenic.  Teflon can be made to burn and some noxious fumes produced, but they are not especially carcinogenic.  

Even after all this, this paper reviewed PFOA exposure and points out that most people in industrialized countries have some PFOA in their blood and this does not seem to be related to a strong incidence of cancer as the level of exposure is so low. 

Flouro-carbon compounds are terribly inert - thats why teflon is so tough.  If PFOA is dangerous, then Teflon is > 10 million times less dangerous.  If PFOA is dangerous, crossing the street is many more times dangerous.  

Even PFOA will be eliminated from Teflon production, supposedly next year (2015).