I have a Garmin eTrex Legend that I purchased several years ago, long before LR4. I set it to record a track, and toss it into my backpack. Later, I download (using Garmin's supplied software) the *.gpx file, suck it into LR, and voila! I have geotaging.
It wasn't a cheap GPS, but it seems to have pretty good sensitivity. It even works in some buildings, let alone in deep canyons.