Hard Drive Imaging Software - Again

Did a 'Dope search and couldn’t find anything recent.
So, I’m adding a 160 gig external USB hard drive to my laptop and want to Image my main hard drive to it. Maybe every day. I fool around a lot and consequently mess up things a lot, so I want to be able to put a good state back on my main hard drive when I do. Mess Up. A lot.
Please recommend some software that’s reliable and cheap. Please, not Norton.

Acronis True Image is well worth the price. You can buy a download version as well.

Thanks, but there’s not enough information on the product for me to drop fifty bucks. It dosen’t even say if it’s Vista compatable.

There is a trial period.