Thank god for e-mails..

"By licking a postage stamp, you will pick up a nutritional content of around six calories."

According to the British Royal Mail, the nutritional content of a single adhesive stamp is 5.9 calories -- although presumably this figure is the caloric content of all the lickable adhesive on the entire surface of the stamp, and therefore a person's actual caloric consumption would be lower (which may explain the far lower U.S. Postal Service estimate of one-tenth of a calorie). The caloric content comes from the sugars present in the wood-based adhesive gum on these stamps, although they have become far less prevalent with the advent of self-adhesive stamps.