Xbees are nice small part used to help small stuff, like Jaluino Bee, communicating together. These are wireless modules, implementing ZigBee protocol. This is quite a tough one, luckily using XBees themselves remains something accessible for the mere mortals. While you could use Bluetooth modules, you may still be interesting in using Xbee as they can join together to build a multi-point network. That is, having several modules talking each others, not just point-to-point communications.
