I personally have one of these guys and find it extremely handy for travel and using in places where you either aren’t allowed to have a tripod, or don’t want to haul a big heavy one around. Check out what you can do with the Gorillapod Focus with X ball head kit in this video from Big Iris Productions.
They put it in some pretty challenging situations and gave it a mixed review. I would add that I find it to work great just to put your DSLR onto and walk around with. I did that while travelling in Spain – put the camera on Gorillapod, and the strap around my neck as usual – but then just rested the legs of the tripod on my hip. It takes all the weight off your neck and I found it really comfortable to walk around that way, ready to shoot.