Need to buy someone a beer or coffee as a thank you for a favor or a good deed? Have trouble keeping track of all those beers you said you’d buy? Foamee is the latest in a string of applications and tools that have taken Twitter to new levels through creative uses of the site’s 140-character updates. Foamee is a free service dedicated to helping Twitter users send I.O.U.s, keep track of their I.O.U.s and then mark them as redeemed so the world will know just how generous you or the other person is. Simply follow @ioubeer or @ioucoffee and send a tweet (preceded by @ioubeer/ioucoffee) to whomever you want to recognize, and you’re good to go. Now a good deed never has to go unnoticed…online, at least.