Mike - Love the drive-on idea for the tower! The link I posted describes a system designed for residential use and talks about sinking the tower and running guy wires, which would be totally impractical for a mobile application. The drive-on idea seems like a perfect solution.
Brett - The plans call for a 260 volt, 5 amp electric motor from a treadmill and the only performance figure given was 7 amps in a 30 mph wind. I think this would work out to 1,820 watts (260 volts * 7amps). I have no idea whether power output from something like this would increase proportionally with wind speed or not but for the sake of argument I'll assume it does. This breaks down to 60.7 watts per every 1 mph of wind.
I found out that the average wind speed near where I live is 8.8 mph (
http://www.wrcc.dri.edu/htmlfiles/westwind.final.html - using data for Denver-Centennial Airport, Colorado). Using this figure I'd average 533 watts...
Disclaimer: I have nothing but an elementary knowledge about this sort of thing and I know I've made some large assumptions in my analysis. If anyone more knowledgeable spots an error, please correct me!
Fisherman - Yeah 30 mph kinda ruins the day, especially when you're still in a tent! I agree solar is probably more reliable, but if one could easily generate 500 watts for under $100 in used parts it might be fun to experiment.
If your numbers are correct, that would mean with about three of these you could power your house for a month. Something seems wrong with that- $300 in wind tech to be power independent (theoretically). I think you might be off by an order of magnitude somewhere- but don't ask me where!