Flashing and re-flashing and HTC Hero with different versions of Andorid I want to try different versions of the Android OS on my HTC Hero (namely 2.2) but be able to revert back to the stock image.

What are the steps required to do this?
How can I extract the stock image from my handset?

I am on T-Mobile UK if that makes any difference.
Do a backup first with nandroid backup, it's included in most recovery images used to flash os roms