The sentry rifle purchase is impressive! Next time you have disposable income, you could always get one of the sentry gun computers: http://en.wikipedia.org/wiki/Grid_Compass
There's one in the Smithsonian Air & Space museum in Washington DC if you're in the area and prefer to window-shop without buying. :)
There's one in the Smithsonian Air & Space museum in Washington DC if you're in the area and prefer to window-shop without buying. :)