Re: You guys should use worldwind.

Thanks for the information Jason. I'll have to check it out when I have some free time. I generally don't like web based mapping apps because of the speed. I try to use apps that run on my machine and pull the data onto my hard drive. The TerraServer site is good in this respect as they publish the programming interface. I have written my own app to take advantage of this.
It seems like the USGS is making it harder to get at the data. They are dicontinuing the free download of the old DEM and DLG files. The download of the newer files seems to only be available through this new web based map. I'll have to research it more to see how it might be done more easily. Maybe Worldwind will provide some clues.