Now there's an app, PopBooth, that lets you host a photo booth in your iPhone. Choose a filter (black and white is always classy, or try the retro "1985"), decide on your poses, and snap away. Your virtual photo strip will be ready in no time.
And as if that isn't fun enough, there are two extra-amazing things about this app: 1. It's free, and 2. For $2.99, you can get high-quality hard copies of your photo strips by mail. They're printed on glossy card stock and will arrive at your door in 3-5 days. How cool is that?