There is a website called money saving expert.com. It is one of my favorite sites. It gives you good free advice on how to save money, which is really useful.
One of the services that the site offers is a mailing list which keeps you informed of new offers, which might be only available for a limited amount of time. The guy that runs the site is called Martin and he seems like a genuinely nice person who is interested in helping people to save money. He is offering to donate 50p to the earthquake appeal for everyone who signs up to his mailing list. I am already on the list. Go here and sign up to the mailing list. You’ll donate money and save money at the same time.