National Geo produces a line of topo maps on CD that is simply one of the best programs I own. I can tell you what a pain it was preparing USGS topos for use in the field before this. You had to have them reproduced, then copied by stinking blue print copiers. And if you are doing recon over a big area you need to carry boxes of maps. Now, you print out combined maps (why does all the really interesting stuff occur at the corners of four maps?) at any scale, in color, on any kind of paper, interfaces with a GPS, or download to some GPS units, draws profiles, calculates distances, uploads/downloads waypoints.... If you spend any time outside in need of a customized map, I highly recomend it.