Collect 5 vouchers from Nestle products to get one free session of dancing, swimming, golf, football or martial arts or one free badminton, tennis or squash court. Other choices of Quad Biking, Clay Pigeon Shooting, Climbing, White Water Rafting, Snowboarding etc. also available.
Coco Shreddies are £1.74 for 500g BOGOF in Tesco online and instore. This means you could buy 5 boxes of Coco Shreddies, get 5 free plus an opportunity to take up any two sessions / lessons of your choice all for just £8.75.
The BOGOF ends on 15th july 08 but the Activities are available until 30/7/09, and current boxes of Coco Shreddies are best before 31st March 09, so no problem with getting through 10 boxes.
You can do as many as you like, as long as you have a voucher, which requires 5 tokens, there is one token per box of coco shreddies.
The website doesn't seem to list all the activities, but promotional boxes detail many more choices / options.