XBee modules provide an incredibly versatile RF communication solution for microcontroller projects, and this kit helps you get started.
Get it here:
http://www.ic0nstrux.com/XBee-802.15.4-Starter-Kit#.UsRocPTFyoM
XBee 802.15.4 Starter Kit
Let your electronic project become wireless with the XBee 802.15.4 Starter Kit.