If you have an HTC phone that runs Windows Mobile, there may be an android port for it. Have a look at www.androidonhtc.com.
The method seems to be to kick off the bootloader from within WinMo, then it boots up android from an image on the sdcard. I think you have to do this each time you want to boot android on the phone....and it appears to support multiple versions of android. There are screen shots of WinMo phones booting android running the Nexus One boot animation and all kinds of other awesome-looking fun stuff.
