I did an early morning set, and it was well worth getting up. I showed up at the Lincoln Memorial about an hour before sunrise and walked around the mall a bit - Lincoln, Washington, etc. Got to the MLK monument just before sunrise. Very, very few people out (of course), which meant it was easy to setup a tripod to shoot.
FWIW - these are all from a Canon G11 with a little Tamrac Zipshot mini-tripod. I can't blow 'em up big, but they came out pretty well with such a small kit.
I don't think that a UWA lens would have helped with the monuments - you generally have plenty of room to stand back on the outside; and for inside stuff I just shot details (like the Lincoln shot here). And I like the angle for the Washington Monument shot with the capital building in the background instead of the usual straight-on with the reflecting pool.