Kellogg's are currently running a 'Feast of Football' promo where if you collect 8 tokens from promotional packs you can claim a free 4 week pass at any Fitness First. This pass entitles you to full access to your chosen Fitness First health club - Free induction and ongoing fitness advice from Fitness First instructors - The use of all available facilities in your chosen club - Entry to free studio classes (subject to availability) - and Free soft drinks and free toiletries.
After a small amount of research I've found the cheapest way to reach the 8 tokens is to buy 4 750g packs of Kellogg's Cornflakes which cost £2.29 at all the major supermarkets. Each pack has 2 tokens meaning 4 boxes will get you the 8 points required for a cost of just £9.16!!! (n.b. mysupermarket.com states tescos is £2.24 a pack but I've just got back from there and they were definitely £2.29. Sainsburys MIGHT be £2.28 a pack but Tescos was closer to me).
These are 4 week trial vouchers so the only caveat emptor is that if you've ever had a free trial at Fitness First or are a current Fitness First member then you won't be elegible for these, but if you haven't then it's a great way of getting a months worth of access to the biggest gym in the UK for less than a tenner! The other thing to note is that the promotional packs are only supposed to be available til the end of July (a weeks time) but my local Tesco had tons of the packs left and you do the claim online using the codes so it's nice and simple. Also the website states the codes and vouchers are valid until the 31st March 2011 so there's plenty of time to claim it once you've purchased the packs.
Hope this helps someone!