If you're throwing yourself at them, they more than likely all ready know. My advice is to keep with it, be polite and respectful, but seem interested in them. But not over interested in a freaky stalker kinda way... Invite them out sometime, but don't make it a romantic thing because it might make them nervous. Just show that you're a friend and you'd like to be more, and they might warm up to you...
but then again, some people like it when others are direct. Either way, I think you should hang out and see what happens.
