Britney Spears posted a video of herself doing a Woody Woodpecker impression.  Sounds like she's put some work into it.  (After it went online, Katy Perry complimented her on Twitter.  So Britney challenged (SEE BRITNEY'S VIDEO HERE) Katy to do her best impression too.  Katy met the challenge by coming to the VMAs wearing a denim dress like the one Britney wore with Justin Timberlake back in 2001.)