My friend Larry recently visited New York City—it's the February 18, 2003 posting (I'd link but he doesn't have permalinks. D'oh!)
From Kottke.org, I visited New York Songlines—an amazing annotated street-by-street guide to New York. Amazing in its breadth and its information structure using HTML to map the city. I can't imagine how long this must have taken, both to collect all the information and then to build it. For example, check out this sprawling view of 2nd Avenue—I'm sure this would mean more if I had ever visited NYC. You get a sense of the size of New York and also the diversity of commerce that Larry mentions.
Great site. And it'll probably get better as he adds more songlines.