Having recently received a major sunburn to a large area of my back, my ears perked up when I heard this story covered on "60 Second Science"

July 31, 2007: 60-Second Science
Caffeine, Exercise May Protect Skin From Sun
Studies with mice found that moderate amounts of caffeine and exercise lowered the skin cancer risk from UV light exposure. Karen Hopkin reports.

Listen here, it will only take a minute.

They said the mice they observed had about two cups a day and mice that received more coffee actually fared worse then the mice who had no coffee at all. Something about the caffeine coupled with the exercise kills off damaged cells, which if they didn't die could grow cancerous.