I started playing a fun guitar-based rhythm game called Frets on Fire. It's designed to be played by picking up your keyboard (like a guitar). Ideally you'll want to press the Function keys (F1-F5 by default, but I changed it so I press F5-F9 instead), and hit a pick key (Enter/Shift by default, but I changed it to the numpad 0 and numpad 7).

The game only starts out with three songs, but you can download a lot of songs on various fan sites, or make some yourself. It's a lot of fun, and it's a good excuse to listen to some of the classics of guitar history, such as Sweet Child of Mine, which is my current LSS. I'm also looking for more Deep Purple songs.