What is a good handheld acre counter?  I had an adjuster for a hailed part of the field walk around the area, and he came up with the exact acres in that spot.  I should have asked him then what he used, but never thought of it.  I want something I can use on quad, or even drive around a field in my pick up and get the correct acres.  I have a Garmin GPS in truck, with software that shows all the 1/4 sections and legal descriptions in Western Canada.  Has all the road allowances, etc.  Can something be hooked into my original GPS, or what?