AskMe: GPS for Trip Recording

Ask MetaFilter: “I’d like to track my route using a GPS, and in the evenings, overlay that day’s trip on a map. For some reason my Google-fu fails me and I can’t seem to find a straight answer to the question: what is a resonably priced GPS unit that will allow me to record my trip? And as a follow-up: do I need special software to do the ‘map-overlay’ thing?” Definitely Rich’s department: both his blog (where he’s started a series on choosing the best software) and his book (which I reviewed in February).