Go to http://jdmcox.com/ for a neat free program that allows you to download topo and aerials from MS Terraserver. After you enter the coords you can download the map/aerial and then scroll left, right, up or down past the map area and then download more. You can create a map as large as you want. If you don't have broadband you may not want to try it though. Also the maps will reside on your hard drive and the files are rather large but you can delete them when you want. The neatest thing is that you can download tracks from your GPS onto an aerial photo. Very cool.
Here's a sample:
Steve
Here's a sample:
Steve