resource recommendations - Is there an easy way (a pattern or plugin) to create urban maps? Inkscape preferred

This is a tall order, but I thought it might be worth asking.

I'm working on a project where I need to basically fake a large urban map: streets, parks, rivers, etc. Essentially I'd like to wind up with something that looks like Google Maps at one or two stages short of maximum zoom.

I don't really want to spend an infinite number of hours drawing it, however.

Ideally, this would be something that I could generate in SVG, but reasonable resolution bitmaps would be fine too.

Gozzy's Map Generator and Dave's Mapper are kind of what I have in mind, but I need urban, not D&D. Suggestions?