Interesting demo of two Tribots communicating

http://nxtasy.org/2006/12/06/a-tale-of-two-tribots/

“The end product was a 2 NXT demonstration using slightly modified TriBots which communicate via Bluetooth (BT) and using a combination of ultrasound (US), motor encoders and two HiTechnic compass sensors. The first TriBot finds and captures aluminum can, and then sends a message to the other TriBot, which in turn finds it, aligns the two iteratively by measuring azimuths using compass, and finally pass the can between the two. All programming was done using NXT-G.”