Future 5000 - Like the book, Future 500, on blast. All the hottest youth organizations in one place.
BYOFL - Database of DIY venues, promoters, bands from all over the world, but most data is from the US.
Generation Change Leadership Directory - The Center for Community Change has put together an amazing list of progressive leadership opportunities around the country that you can take advantage of.
Do DIY USA - A great (not to mention super up to date) resource of DIY venues and houses around the United States.