Backing up a running guest

[cybermage]

I'm wondering if there is a way to backup a running guest automatically. I'm assuming this would require suspending the guest in a script, followed by backing up the disk image, then resuming the guest. I'd like this to happen on a cron job. Actually, I'd like to backup the disk image while it's running, but that could be dangerous to the data, no doubt.

Has someone written some automated scripts to do this, or am I on my own here?