There actual name are called Zentai suits, you can get a whole range of them like in the materials like nylon/spandex. You can get customized ones like ones with nipple wholes and get a sleep bag variant (Just a bag) lol
I think they are pretty cool, I want one and wouldn't mind being tied up in one, I think my GF has one though, I think I saw a glimpse of one in her draw, or maybe it was just tights. But yeah they're pretty cool.
Here's the Wikipedia article where I got this information:
http://en.wikipedia.org/wiki/Zentai