Funny easter egg: If you do db.unicorns.remove({}) after it asks you to list the collections, typing "db.unicorns.count()" will redirect you here: http://www.thinkgeek.com/caffeine/wacky-edibles/e5a7/

(At least I think it's an easter egg, I didn't get all the way through. Maybe murdering unicorns is a normal part of the tutorial)