There is a great little tutorial over at Macworld today on how to use your Mac as a musical alarm clock, using just the tools that are installed with OS X 10.4 (Tiger).
It’s very simple to do… it involves Automator, iTunes, and the Energy Saver Preference Pane. The Energy Saver Pref Pane boots your Mac at a specified time, and Automator takes care of the rest. Here’s a tip for you… if your Mac requires a password to boot up, this tutorial won’t work.