Would you Tweet your credit card purchases?

The Internet marketing guru who created one of the Web's biggest ad networks has a new venture, and he'd like your credit card number.

Oh, he's not going to sell you anything. He just wants to keep track of where you shop, what you buy and how much you pay for it -- and he wants to share that with all your friends.

Is this cool or just kooky? This New York Times article describes the initiative, which is in beta mode (meaning that it's still being tested on a trial audience of the founder's acquaintances).