Another new device that's just hit the shelves is the Shift Register / Expansion Module, which gives you a convenient way to drive additional output lines if you start running out of I/O on your Arduino.
Using just three I/O lines on your Arduino you can control eight outputs, and you can even daisy-chain multiple modules together to drive even more: with two modules you can drive 16 outputs with those same three I/O lines!
To see an example of how to hook it up and sample code to drive it, check out the Shift Register / Expansion Module Quickstart Guide.
