[M's_Fan]

I thought this was interesting, from the article:

It's simple physics: a bat that's been hollowed out with a drill, its innards replaced with cork, will be lighter without sacrificing power. Lighter bat, quicker swing, better contact on the pitch. That's how the thinking goes, anyway; MythBusters looked into it and found that the ball comes off a corked bat markedly slower, and concluded that the cheaters have only been cheating themselves.