Financial talk

Hi, Today I got a letter about a school skiing trip to Italy (Feb 2009) and it costs £725. My mum and dad can probably afford it, but I don't want them to pay it all, I feel bad. I want to raise some of the money myself, apart from things like babysitting (I do already) and paper rounds (I'm looking for one) how could I make some money? Thank you :) i'm 13 by the way.