Nothing will make you grumpier than actually having to go to the Post Office to send a piece of snail mail. In honor of the antiquated practice of delivering physical pieces of paper with hand-written messages on them (just typing all of that made us grumpy), Zazzle has created a usable U.S. postage stamp featuring feline Internet star Grumpy Cat. According to the site, “Zazzle’s medium custom stamps fit especially well on greeting card or RSVP envelopes.” The card may say “Happy Birthday,” but the stamp lets the recipient know, “this is how I feel about sending this greeting out of social obligation” …
