The idea behind Bump is very simple: Two users run Bump on their iPhone at the same time, “bump� their devices together and by doing so exchange contact information they have previously chosen to exchange. No typing, no writing, no handing over of business cards…simply the coolest way of exchanging personal information.

This is what the application looks like on my iPhone:

The app works on WIFI as well as on 3G. There are two parts to Bump: the app running on your device and a smart matching algorithm running on Bump Technologies servers in the cloud. The app on your phone uses the iPhone's sensors to literally "feel" the bump, and it sends that info up to the cloud. The matching algorithm listens to the bumps from phones around the world and pairs up phones that felt the same bump. Then the contact information between the two phones is simply exchanged.

Bump is completely free for the moment, but their goal is to release a more complete version in the near future which will allow not only exchanging contact information, but also pictures taken with your iPhone.

Check out a short demonstration here:

For more information visit http://www.bumptechnologies.com