polaroid-o-nizer has swept flickr, and it's quite obvious why.

In case you can't figure it out, it's a little web app that takes a picture and turns it into a digital polaroid. You just have to have the picture up on the web someplace for the web app to strip it from.

There's even a spontaneous group sprouting up on flickr devoted to it: Calling Card.

It's a LOT of fun, you should try it. The only drawback is that the output isn't large enough for some of the cool geeky stuff I want to try out.