So Barack Obama and John McCain have been arguing over who is the poorest rich guy. McCain was asked how many houses he owns. He said he didn't know -- would have to check with his staff.

Huh?

His staff got right on the matter -- and promptly determined McCain had four houses. Then, reporters started digging around and found three more houses. And as of 7:41 p.m., they've found another one --- for a grand total of eight homes.

Obama is making some political hay about McCain's memory lapse -- suggesting people who live in eight houses shouldn't throw stones.

"I suppose if you have seven or eight houses, the economy looks pretty sound to you," Obama said at a rally in Chesapeake, VA. "But if you don't have one house and you have trouble making the mortgage payment, then the economy looks pretty awful."

In response, the McCain campaign decided to bring up Obama's concerns about the price of argulua --- and his affinity for vacationing in Hawaii. And now, McCain has launched a new campaign ad: