He'll probably hate me for this, but a few years ago I contacted Mike personally and asked him if he had a copy of the Sewer Pipe Black Market map without the legends on it. Not only did he respond right away, but he sent me a very high resolution version that I was able to print out on several sheet of paper and tape together, leading to one of the more memorable encounters of my campaign. Thanks again, Mike.
Wow. That blew me away when I saw those maps. About six months ago, I was looking to run an adventure in a mansion and did a search for mansion floor plans. And those are the EXACT floorplans that I used. Of course, it took me a LOT more work to convert it to a graph grid. I wish I'd seen this article a lot sooner.
I acutally use a battle-mat with dry-erase pens. It measures 42" x 36", reversable, and has both squares and hex 1" boxes. If I am not being lazy, I will draw out the major maps on one side and smaller encounter based items on the other. Works rather well...