A simple and helpfull tool to don't make installing and backing up ROMs easy as pie!
It really becomes tedious if you constantly try out new ROMs and therefore delete your old ones.
Booting into recovery -> manually backing up -> -> reboot into recovery -> manually installing the new ROM.
Well, not anymore! Rom Manager installs a new ROM or backs your old one up with one simple click!
There is a free version and a paied one availible:
-Install ROMs automaticly
-Back up ROMs
Paied version (3,56€):
-Download Premium ROMs
-Update notifications for your ROM
Developers Website: http://www.koushikdutta.com/2010/02/clockwork-recovery-image.html
Availible at the Android Market.