I for one love tourists. They do not annoy me, I think its cute when they get excited about things like the Metro, the Capitol, the White House and various musems and monuments, I always gladly help them out with directions or suggestions when asked, and they provide me with many moments of comic releif when they ask funny questions or unintentionally annoy crabby locals on the street and on the Metro.
That said, share your favorite tourist encounters, good or bad.
Mine probably came this morning when a guy in his 50's, wearing shorts and flip flops and a "beachy" shirt, who said he was from California, came up to me on 17th and Penn NW and asked "do you know if the Congress is near here?" I told him it was at the Capitol, to which he replied "really? since when?"