(Quote from http://www.androidfanatic.com)
UPDATED VERSION!!!I have created and installer and bootloader fo getting Debian running on your Android (G1 at the moment) device, the whole install process will take you about 30 mins, and leave you with access to the full plethora of programs available in Debian and let's you continue using your phone as it was intended to be: as an Android device with all the capabilities thereof.
I use the Android Dev Phone since one week now and for now I'm happy with it....but I miss some essential parts (VPN Client). I think I know what I'll do this weekend ;)