"Image backups" are IMHO a very
bad idea. The data is locked in till the image is recovered/mounted.
What's important is your data, not your (exact) current setup. When you get into a recovery scenario, you may not even have the same hardware - or even be a guest.
Mondo creates a liveCD you boot and recover from. Allows changing size/type of partition/fiesystem - very comprehensive. Can be slow though - especially if you verify all the data as it's created. I use it for "doomsday" backups - the entire machine (Windows and all) to iso images which I keep 3 copies of. For day-to-day backups I just use filesystem aware tools - of which Linux has truckloads.
Another option which I haven't played with yet might be http://relax-and-recover.org/