evilsheep, thanks, that was good of you - i'm realising pretty quickly that volunteering is pretty expensive - i found something that sounded ideal but was £1500, which was a bit above budget! and for a lot of cheaper things, you need to be 18...thanks for the help there tho.
mandy, thanks for the link, and gillsfan, that's great to know you were able to go and do it, what sort of things did you do there? i've emailed them to see if i'd be able to go there....thanks a lot for all the advice.