I have been looking for something fun to do for a day and thought Zorbing looked like a laugh. I have been keeping an eye out for a while but special offers are rare and the average price is normally £25 per person. Zorbing south seem to work out quite cheap at £45 for 2 people either in a hydro Zorb (2 of you in a zorb along with a bucket of water) and for harness Zorbing (obviously where you are harnesed in). This is not a bad deal on its own but they currently have buy one get one free on every day except saturdays.
I guess that means you can get 4 of you to have a go for £45 or 2 of you to go twice! Bargain