An American Soldier recently stationed in Baghdad was bitten by a Camel Spider which was hiding in his sleeping bag. These spiders have the ability to jump very high and when they latch on to you, you will be injected with a local anesthesia so you can't feel it feeding on you. These spiders don't just suck out your juices like a normal spider, they eat flesh.
Camel spiders, also known as wind spiders, wind scorpions, and sun scorpions, are a type of arthropod found (among other places) in the deserts of the Middle East. They're technically not spiders but solifugae (although, like spiders, they belong to the class Arachnida). Camel spiders are the subject of a variety of legendary claims, many of them familiar to Americans because they were spread by U.S. servicemen who served in the Persian Gulf War in 1991, and re-spread at the beginning of the Iraq War in 2003.
More spider info about the Wolf Spider and Brown Recluse Spider at WolfSpiders.net and BrownRecludeSpiders.info respectively.