Have an Answer?
Apply to a lot of places, then pick a few of the more likely places: the places you think you'd have the chance of being accepted, and the places you think you would most enjoy working). Study the papers these laboratories/groups put out, to familiarize yourself with their research. At the very least, read over the abstracts. Then do it again. Be ready to at least superficially discuss the particular research they've been doing lately, and demonstrate that you have insight. Prove to them that you're interested.