A new phenomena brought to us by the fine people at Think Geek.

The Shower Shock Caffeinated Soap, is an all vegetable based soap, and is very easy on the skin. Scented with peppermint oil and infused with caffeine, each bar of Shower shock contains approximately 10 servings/showers per 4 bar with 250 milligrams of caffeine per serving.
No, you don't eat it, the caffeine is absorbed through the skin...