We went on (or rather, in) the Zorb in January 2008. Basically it's a big inflatable ball with some water in the middle to stop you spinning so much (the water helps you float in the miidle of the ball as it spins rapidly outside).
I wanted to use the Zorb where you are strapped into the inside (that causes the Zorb to spin much faster) but the winds that day (and low walls surrounding the Zorb area) meant that wasn't possible. It's also why my ride was down the winding track as opposed to a fast run...we actually saw one ball almost go over the boundary fence with someone in it when it took the fast track and bounced.
Whilst the video is a bit tame, it's a great ride and we all enjoyed it!