I've never tried this, but it might work....

You can get "paper" that allows you to make iron-ons with an inkjet printer. Walmart, Staples, Office Max, they should have it. So.... you scan a topo map, or use something like TopoUSA, and print it (backwards?) on the paper. Add a cool iron, and volia! It isn't as good as a map printed on silk, but a lot cheaper, and you can customize for your area.

Cut your own map clothes from white cotton sheets, the twins are probably the best buy for this. If you want something a little less obvious (say, someone like Ben), you can get a tan sheet. Use a couple of the iron on sheets, make sure they are lined up, and carry it like a scarf or towel. If you wanted to be really spiffy, even though it might make the map a little harder to use, get neon orange or pink nyco from a fabric store. Map and signal panel!