(1) Yes, you can make a Nandroid copy of your present setup and it will appear in a directory of the same name on your SD card.

(2) Yes, you can do a Nandroid recovery from the file in the Nandroid directory. Both items (1) and (2) are done from your RA recovery mode which you boot into by holding down the HOME key and tapping the power key.

You can do this as many times you want, have as many backups as you want and can always go back to any of them. One of the great things about rooting. You can rename the Nandroid files with a name that makes sense about the image that you made, just remember: NO SPACES IN A NANDROID NAME!!!!

Good Luck -- Have Fun -- good group of folks here --- Bob --