This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
i phne Bump App:
There are two parts to Bump: the app running on your device and a smart matching algorithm running on our servers in the cloud. The app on your phone uses the phone'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 we just route information between the two phones in each pair.