Being one of the many people that has an iPhone I've got used to the fact that the battery life is notoriously rubbish, so last year I bought myself a cheap phone which was about a tenner to take to Glastonbury with me...
The only problem was that I had to buy £10 worth of credit as well - which was really annoying seeing as I'm already on a contract I was basically throwing away a tenner!
Anyway, been trying to find this phone and cant find it anywhere... So gave O2 a call and said "look theres some phones on your website for £9.99 but you have to buy £10 credit as well... seeing as I'm on contract can I just pay the £9.99?" and they were like "sure, no problem, you can have free delivery too!"
So just a little heads up really for anyone out there already on a contract thinking of buying a cheap phone that you don't have to worry about losing!
Oh also he said that it comes with a complimentary sim-card, which you can just keep in a drawer at home - if you do manage to lose your phone, just give them a call and they will cancel the lost sim, and activate the one shoved in your drawer for your existing contract - so no hanging around being without a phone for a week when you get back!
Last year I also bought a spare battery from Ebay which was about £4 and after my iPhone died on the wednesday night, I just switched the sim-card and had a phone all weekend - without having to queue for hours at the chill n charge tent!