If you don't have a built-in nav system, you can inexpensively purchase an older Garmin Nuvi GPS.
The widescreen models are easily found on Craigslist in near-new condition with all accessories, or even BNIB, for -.
The 265WT is the one I bought; it was and while the box had been opened, everything inside the box was still sealed. There are newer series Nuvi's, but they will cost more and you really don't need the extra features if you're on a budget.
To find your map version, from the main screen press Tools - Settings - Map - Map Info. Delete the old map from your Nuvi (filename is "gmapprom.img" in the "Garmin" folder).
It will say something like "CN North America NT 2011.10". I think there are 4 updates per year; the next one will be 2013.30. Download the unlocked CN 2013.20 map via a torrent program.
Easy GPS calculates the area of any Garmin GPS track or route, making it a perfect tool for calculating acreage on your farm, ranch, or business.
Read our tutorials on using Easy GPS and Expert GPS to calculate area.
I think the unit has a glitch that MAY be correctable by resetting the unit.