Here is an app that is worth every penny and then some. I love the interface with the retro look and the retro photos. You can play with this forever. I wish I had one of the original cameras this was based on. The original app is $1.99 and each of the 5 additional sets of lenses & films are 99 cents each. A lot of cheap fun. You get this through iTunes, of course.
6 lenses + 7 flash options + 8 films = 336 different combinations. Yesterday I found photojojo.com which has a great guide to this very thing. You can look at the effects and choose the lens/flash/film combo you want to try.
My new Facebook photo was taken using the Lens- Lucifer, Film- Float and Standard Flash. As I said... lots of good cheap fun here.