I’d totally try and be the intern for pinboard.
The money is great for a summer job, but that’s not the important part. pinboard seems interesting, it’s a real service, and it’s (I assume) small enough to understand from top to bottom. Contrary to, say, a Google Summer of Code project, you get to touch a real existing service, and from what I can tell from the blog you get to do it with a smart and funny guy.
You’ve got five weeks left; even if you’re in the middle of exams right now, apply!
(And if you do, why not add the features to merge and rename tags while you’re at it?)