These things get big. Not kidding. Bringing cell phones along is recommended, and some conventions even rent out walkie-talkies. Beyond just the mere scope, it may be worth it to impart the basic geographical structure of your average convention to make it clear why you need to keep your head about where you are and not lose people: it's organized like a supermarket, but with dimmer lighting and more people. A lot more people. And once you've seen fifty geeks, you've seen them all, to say nothing of the stands and booths people set up. It's not quite as frightening as getting lost as the cat show that was using the convention center last week, but it's close. Incidentally, if you see any stray Persian cats, inform the center manager.