so this is a little off subject. you can get a hand held GPS for less than 200 easy. You jsut switch the measurement to Military Grid Reference System. MGRS and go. It will give you .10 kilometer through a solid kilometer. As we all know, .10, or 1/10 of a Kilometer is 100 meters.
I am pretty sure that you can use most GPS and switch to standard instead of metric, but then figuring out the range thing is a little more difficult for example to get 100 yds.
100 meters is roughly 110 yards though
Currently, I use Garmin GPS 12. I have had it since July of 1999. I think i paid about 175 for it back then. And since then, the price for the basic model has come down. You might find a good GPS for a little over a hundred now, without all the bells and whistles like road maps and such.