The basic idea is that any GPS logger that exports a .gpx file can be used with any digital camera. Assuming the clock on your camera is correct, during post-production you sync the .gpx data file with your photos using Lightroom or other software. Your location data is matched to your photo based on time (for example, at 4:05:42, you were at such-and-such coordinates).
Lightroom 4 has .gpx import built-in. For Lightroom 3 or earlier, you can use the donationware plug-in from Jeffrey Friedl called GPS Support. If you don’t have Lightroom, Mac users can use MyTracks (works with JPGs, not sure about RAW files).
In early 2011, while preparing for a trip to London, I knew I would want to geoencode my images. I don’t own an iPhone; for many users, that would be the easiest choice. So I knew I had to purchase some kind of GPS unit.
The main problem I had was getting the logger to sync with my Mac. If you are a PC user, you’ll have no problem; the units generally come with a small-size CD with PC software on it. On the Mac, you have to download third-party software that will sync with your unit. Most (all?) Garmins will sync with Google Earth directly. For other units you can use the free HoudahGPS or the inexpensive and very elegant MyTracks. Most GPS loggers sync over a bluetooth connection; so you have to configure your bluetooth settings properly, and get the software to download the file. This requires some amount of fiddling with settings to work, even in the best of circumstances.
I began with a handheld Garmin 60C, which I use for hiking and geocaching. It syncs easily with my computer over a USB cable connection, and the unit is accurate. But the battery only lasts a few hours, not long enough for a whole day. Plus the size of the thing is relatively large; carrying this big thing around London was not something I wanted to do.
So, I ordered the iGotU (US$60). The plastic on the logger broke pretty much immediately. I sent it back without further testing.
Then I spent a little more and got the $100 QStarz BT1300ST, which is a beautiful little unit. The battery lasts all day, and it’s small and has a nice keychain attachment. I was able to get it to occasionally sync with my desktop iMac, but it never sync’d with my MacBook. It appears to be highly accurate, but since I couldn’t reliably sync it with the MacBook I would have with me in London, I decided to try another unit.
I then got a Wintec WBT-201, it is almost as small as the QStarz, though noticeably fatter. Luckily, I can reliably get it to connect to all my macs. Unfortunately, it does not appear to be terribly accurate. During a walk along the south side of the Thames River, the unit had me crossing the river zigzagging from the north side to the south side several times, as if I were swimming across the river again and again.
Actual route taken: Started at the Tower of London (north side of the Thames); crossed Tower Bridge. Walked west along Queen’s Walk (for the most part) to the Millennium Bridge.
EDIT 7/4/12: I have since used the Wintec unit on a trip to Philadelphia and Gettysburg. In open country, such as on the Gettysburg battlefield, the unit is extremely accurate. Here is the map of our bicycle route on the Gettysburg battlefield, you can see it hardly deviates from the path. In a couple spots, I do walk around while the tour guide speaks, which accounts for some of the odd-looking spots. And I still haven’t been able to sync the Q-Starz with my Macs. Perhaps its Bluetooth ability is broken; I have no way of knowing.