The Stamp-A-Ma-Jig is awesome for lining up those wood mounted rubber stamps perfectly. It's hard to see exactly where the rubber is underneath the wood, and a lot of times, really cheap rubber stamps can be mounted at a skewed angle.
I used it to line up some butterflies for a card I was making for a friend. I was already working on this card when I started taking pictures. I'd already used my little Stamp-A-Ma-Jig for the "congratulations" sentiment.