PalmGear says it's for Tungsten but saw this app recommended on two Treo sites.

If you’ve missed those mornings when you used to wake up to the blaring radio…or, if you’re sick of the same ‘ol ring tones that you’ve been using for your phone alarm, then here’s your answer! Fabian Heuwieser has released mp3 Clock 1.0 that will allow you to wake up to your favorite mp3.
http://www.treohq.com/content/view/471/66/

Not quite free but at $2.95 ....