Mattel's coming out this summer with an Twitter-enabled dog collar. The collar detects when your dog moves or barks and tweets one of 500 pre-written messages. It's not for sale until this fall, but Mattel's Puppy Tweet, a tweeting dog collar, has already generated blog post after blog post. Every time your dog moves, barks or growls, the collar sends a pre-programmed tweet... chosen at random from a selection of 500 options, including "I bark because I miss you — there, now hurry home" and "I finally caught that tail I've been chasing and....OOUUUCCHHH!" It's Mattel's first product for pets, and the company is careful to say the device, with a suggested retail price of $29.99, is "just a toy."