Automate playing a rhythm game.
Most of the detail on the Guitar Hero 3 bot is now on a site dedicated to both the GH3 Bot and the Rock Band Bot called Rock Bots.
An excerpt from the GH3 Project
The bot, which is technically an application that runs on a PC, controls a Guitar Hero 2 Controller via a USB interface device. In theory it could also be done with a wireless guitar hero controller or a standard wired or wireless Xbox 360 controller. The PC application reads 'tab' files that I have created in one way or another and plays them through the controller. (Tabs are what guitarists often read, I have called these files tabs files as they use a similar theoretical approach.)
For more information: