Reliable Source: Caroline Kennedy chows on a cheeseburger in D.C.

Hey, isn't that...U.S. Ambassador to Japan Caroline Kennedy, dining al fresco with three pals on Friday night at Cafe Deluxe in Cleveland Park?Ever the booster of American cuisine, Kennedy -- who is based in New York when she's not in Tokyo -- ordered the most Yank-fied of dishes: cheeseburger and fries, a spy says, washed down with red wine (domestic, we presume?).