That is a solpugid, aka solifuge, sun spider, wind scorpion.
It's in the order Solifugae.
These arachnids are supposed to have the largest jaw-to-body size ratio of any animal in the world. They have four jaws; two on top and two on bottom.
I used to see them all the time where I used to live. They would get into the house, and I'd catch them in a jar of dirt, keep them for about a week, feed it a few baby crickets, then let it out. They don't keep well in captivity, which is why I always released them soon. I've seen both the thin-bodied and the fat-bodied kind. If you tease it a little with a stick they will open up their four jaws and make themselves look like that alien guy from the movie "Predator", only worse.
The biggest one I ever caught was about two and a half inches long (not including legs) and about as fat as my thumb. They don't get much bigger than *that*. Usually they're about an inch and half long, with the thin-bodied type being about the diameter of a pencil, while the fat-bodied ones are usually about as fat as a small almond.
I remember one time I dropped in a cricket, the solpugid leaped forward and SNAP, chopped its head clean off its body so hard the cricket's head flew off and landed about an inch away.
Here's some links.
Pics of weirdly colored ones:
[url]museums.org.za/bio/arachnids/solifugae.htm[/url]
Info page:
[url]earthlife.net/insects/sunscorp.html[/url]
Page with links:
[url]ufsia.ac.be/Arachnology/Pages/Solifugae.html[/url]
P.S. - Be careful. They CAN and WILL crawl up glass with their "antennae" (pedipalps). They have little suction things on the ends of them.