In light of the fastboot flash method I was thinking of a way to be able to keep my current setup as a backup while i experiment with other images. For that I wrote a script that uses adb to dump the data for the boot, recovery, system and data partitions.
When this script is ran, it will dump these images in your current dir.
Boot into recovery mode (home+power) to use.
Requires RC30 v1.2 recovery.img - due to a bug the RC8 v1.2 there is no adb shell. (this script needs adb shell as root + busybox in recovery mode to work).
PLEASE NOTE: I haven't actually flashed the dumps back yet, I will be trying that tomorrow. Brave souls willing to test that do so at their own risk!
Bug reports or own improvements welcome.