Well. I just saw this thread.
All of the Tim Powers books that I've read probably qualify as urban fantasy, taking place in the present or in the near (say fifty or sixty years) past. I don't think that's all he does, though. I'll be finding out...since the con this weekend, I'm on a crusade to find and read more of his work.
By the by, he said this weekend that he's currently working on a novel that takes place in the 1980s in Pasadena, but that hinges around some thing that happened while Einstein spent some time at Cal Tech in Pasadena. Sounds really interesting, and I can't wait - but he sounded like he was only about half-way through the writing at present.