Haagen-Dazs' Flavored Stamps.

Haagen-Dazs and the Austrian Postal Service have teamed up to launch flavored stamps (as part of the ice cream maker's "Let Your Tongue Travel" ad campaign):

"They infused flavors like Cookies & Cream, Macadamia Nut Brittle and Strawberry Cheesecake into the adhesive on the back. As you licked the stamp, you actually tasted the flavor!

Link - via grow-a-brain