MicroView Digital Compass
Contributors:
AGlass0fMilk
AGlass0fMilk 
Resources and Going Further
There are a many more cool projects you can make with the MAG3110 sensor. If you combine the MAG3110 with a few other sensors, you can make a variety of projects that involve location and orientation sensing.
Check out Shawn Hymel's Adventues in Science: Using a Magnetometer as a Compass and example code for ideas:
For more sensor fun, check out these other great SparkFun tutorials:
BadgerHack: Sensor Add-On Kit
Turn your Badger or Redstick into a temperature and soil moisture sensing display with the BadgerHack Sensor Add-On Kit
LilyPad Light Sensor V2 Hookup Guide
How to hook up the LilyPad Light Sensor as well as some project ideas and example code.
Advanced Autonomous Kit for Sphero RVR Assembly Guide
Get your Advanced Autonomous Kit for the Sphero RVR built up with this hookup guide!