I'm looking to turn one of my extra powerbook duos into a simple alarm clock for my endtable. I figured it would make the perfect alarm clock: Large, dimmable LCD display, small footprint, and mine runs off a CF card so totally silent (until I need it to wake me up!).

There are plenty of these for OS X that will play MP3s etc at a certain time and display the time full screen otherwise. Is there anything for OS 7/8/9 that I could use?