I just finished a project using Linx Technologies 900 MHz transceivers. Mouser has them: http://www.mouser.com/ProductDetail/...rSQqdnUWL1o%3d

Super simple to use - these are "air wires" meaning they don't force a fixed protocol on you; you can transmit/receive just about any kind of data you want (literally, serial, PWM, etc). This is a "big deal" if you don't want to get bogged down in the details of using a fixed protocol for your data.

As usual; the data sheet will be your best friend. They have demo systems available (I highly recommend buying the system to jumpstart your project - you can hook your uC to the board and be underway in minutes).

Good luck!