17th birthday party ideas?

I'd really like to do something for my birthday this year as I always seem to end up doing a cinema trip or a sleepover >< So I was planning on renting out the big local hall and having a huge club-type party, but I've left it a bit too late to book and it's very expensive >< So I was wondering if anyone has any cheaper, alternate ideas? :D I was also thinking house party but I dont have a house big enough! >< So yeaaaaah, I'm not having much luck thinking of anything! ANY ideas would be very much appreciated!! ^^ and something I can organise within about 2 weeks and that has a decent amount of guests if possible in your ideas pleeease!! xD Thank youuuu!!! ^ ^ xxx