I recently won a grant from Michael Jordan Foundation to teach kids about real world mathematics. The lesson I submitted involved GPS technology and mapping programs.

Now I need to spend his $$$. I am looking for 15-20 BASIC GPS units. I dont need something fancy, and want to keep the cost down so I can get more units. Anyone know of a decent price on a decent unit? Even a place that will cut me a deal because I plan on buying so many? I also need a user friendly mapping program that middle school kids could operate. I thought I'd turn to the experts!

Any help you can offer would be greatly appreciated.