http://gumspots.com/

This was ITP alum Jason Kauffman's thesis project. He's added some crazy features, and I guess the whole thing is some sort of mobile platform, but the coolest thing about it is the business cards. Each one has a gumspot pattern on it. You take a picture of it and send it via MMS and you'll get information back on the person who's card it is. There's also this other feature where you just send in a pic via MMS and you'll get another pic sent back to your phone.