Even if you're not a Harry Potter fan, I think you'll find this funny.
Warning: Spoiler Alert (if you hadn't read to the end by now...)
Another warning: Strong language.
May I introduce you to the Harry Potter and the Deathly Hallows Review Rap...
edit:If you want the lyrics, they're in the youtube video description. URL:
http://www.youtube.com/watch?v=rF3SE4pZUuk