I got a "Miraclesuit" from Cyberswim.com back in early 2008. I was about 10 lbs overweight at the time, and had a corporate shindig to attend which would have pool activities. The suit worked well, it did make my stomach look completely flat when I sucked it in, and reasonably in-shape when I didn't.

I got pregnant later in the year, so put the suit away for awhile. I now have a 3-month postpartum body which is extremely saggy in the middle, and I weigh 20 lbs more than the first time I wore the suit. It still fits without making me muffin-out around any elastic edges, and it is still holding in my stomach.

Granted, when I suck it in now it doesn't go completely flat. I think I'd need something more akin to a steamroller than strategically engineered spandex for that at this point. But when I suck it in, it does make me look reasonably fit for a woman with a 3-month old. And when I don't, well, at least I look like a plump sausage around my middle instead of a deflated balloon.

I really didn't expect it to help as much as it does in my current state. But I am pleasantly surprised, and while the fit certainly qualifies as snug, it's not uncomfortable. For me, the suit is well worth the $150 or so I spent on it (most of the styles are in the $130-160 range last year, haven't checked lately). I wouldn't bother getting one if I was just hanging around the neighborhood pool (unless I was single!), but I got it for hanging around the hotel pools in LA (which I don't recommend if you are not a size 0 and you're prone to depression or feelings of body inadequacy. . .) and of course for wearing in front of coworkers. So now I'll wear it anytime since I already have it.

One thing to be aware of if you get one, the instructions indicate that the "miracle" fabric is very particular about its care. I handwash it with gentle soap right away every time after I take it off. Another reason you might not opt for it as your "everyday" suit.