Has anyone used or tried the new ab machines?

I've been seeing tons of ads for those electronic ab belts, the ones where it stimulates your muscles into contractions. Has anyone used or tried them? Do they work? I was thinking if they do, I'd like to get one! Thanks in advance!

We greatly appreciate your interest in helping us build our Q&A database. To discourage vandals from posting garbage, however, we require people to register before posting.