Not sure whether this should go under Pets or Top Tips or Bargains........but if you have a cat or dog who has Hill's Pet food this is worth doing as the food is quite expensive.
All you have to do is to register on the Hill's Pet food Site http://www.hillspet.co.uk/ you can download a £5 voucher :D
Just got back from the vets with a nice 'cheap' bag of food ;D