For the last six months, I've been taking a photo with my iPhone every day. I've been doing this for two reasons, partly because I want to demonstrate that the iPhone has a crappy camera and partly because I wanted the discipline of having to take at least one photo every day. However, with the right conditions and a little luck/effort, you can take some ok pictures with it.
Absolutely no post-processing at all has been done; these are all as they come, straight off the crappy lens of my iPhone 3G.