This may be useful depending on how you use it, but may still need some work in Photoshop afterwards to clean it up. [Link]
I suggest using a city with non English names or using toner/terrain lines + background (combined in Photoshop) to map out a design. If you pick out a small enough town you can do something that looks grander than what it really is. For example:
Aside from that, I haven't found too much yet and I've tried a few times to find a city generator. There may be something out there but a lot of it caters towards D&D designs.