This is my favorite shot from the Smithsonian Air and Space Museum (on the National Mall). The aircraft is on display in the Military Unmanned Aerial Vehicles exhibit within the museum. It it has a very sleek. stealthy appearance, but is still pretty small for a UAV (to me it looks like a combination of the B2 and the F117). Enjoy!
Some interesting tidbits from the Smithsonian site:
"This X-45A, named The Elsie May, accomplished several firsts during testing. Among them: the first autonomous flight of a high-performance, combat-capable UAV; the first weapons release from an autonomous UAV; and, with Air Vehicle #2, the first autonomous multi-vehicle coordinated flight. Only two X-45A scaled-down technology demonstrators were built. Flight tests successfully concluded in 2005."