I've got 4 of these from McDonalds (they're printing them on the tray mat thingies at the moment),
£8 off entry to Chessington World of Adventures, one voucher per person per transaction (presumably you need to pay seperately to use more than one).
Valid for whole season bar a few select days.
Email me at huffahorse at hotmail dot com and you can have them - let me know how many you need, send me a SAE and they're yours