I wouldent recommend using it on anything but a 2.1 and above device slower phones like the G1 and the eris have reported issues.
Works like a charm on my HTC Incredible and Motorola Droid.
Here is the link to the APK if any of ya'll are intereted
http://github.com/pcgod/mumble-android/downloads
P.S I didnt make this I just found it and helped the IRC people install it on their devices.