The Space Explorer (by Logitech) gives users a 3 dimensional navigational experience allowing simultaneous inputs for a more fluid and realistic environment. Mouses allow you to pan, twist, spin, or zoom in, but you can’t do all of them in one simple twist.
I’ve played around with the Space Explore and it takes a few hours to get use to. Once your hooked it’s as intuitive as most mice are in any 3D CAD package(I favor Solidworks). I’ve yet to completely convert over to this mouse, but it saves a ton of clicks and twist while making you look cool with blue LEDS hovering under the main knob. I’m not sure if I’m ready to fork over $299 for this, but once the price drops some, I’ll be hooked and sneezing the products amazement around to all my friends.