Golf GPS devices have evolved from simple distance readouts on modest displays, to today's high-resolution touchscreens, with video flyovers of holes, distances to hazards, and advanced stats analysis.
Costs have come down, as well, and not just for the devices, but also for access to course map databases, which are now mostly free.
Golf GPS devices have also split out into three different categories, including handheld, wristwatch, and smartphone apps. This presents a lot of options.
Golf GPS Watches
The place to start is your personal style. If you want nothing but distance to the hole from anywhere on the course, you may be best served by a golf GPS watch. The great thing about a watch is that it's always with you, and you don't need to constantly take it in and out of your bag or cart, as you typically do with a handheld.
Garmin offers two golf GPS watches, the Approach S1 and the Approach S3 ($349). The S3 is the newer model, and fits a lot into a small device, including a worldwide, 27,000-course database (updates are free online), a touchscreen display (works with a golf-gloved hand) that shows distance to the front, back, and middle of the green, as well as distances to doglegs and layups. You may also keep score on the S3, and measure shot distances. Garmin also sells an Approach S1 North America ($249) with 18,000 North American courses in its free-to-update database.
Motorola has also jumped into the wristwatch golf GPS game with its MOTACTV golf edition watch ($299). the Golf Edition may be used as a separate, 1.6-inch screen device, or clipped in to a rugged plastic sports watch band. It's the only golf GPS to wirelessly sync (via WiFi) round results and other stats to your computer. In addition to basic distance information, the MOTOACTV can keep scores for up to four players, and has features such as steps taken and calories burned.
Handheld Golf GPS
Handheld golf GPS devices, in addition to the dedicated type installed in golf carts, were where it all started. Handhelds have seen dramatic improvements in features and performance, while holding fairly steady or dropping in price. One of the biggest price differences is the move from costly monthly or yearly subscription plan for access to course databases, to free course databases and updates.
I go into the full details about handheld devices in my big buyer's guide to handheld golf GPS, so I won't try to cover them here. The latest trend in handhelds is smaller size (the new, color-touchscreen Garmin Approach G6 measures just 2.1 x 3.7 inches and the Callaway upro mx measures 4.0 x 2.0 inches, for example) that fit into a shirt pocket. Handhelds can now also provide detailed course flyovers, detailed hole maps with distances to hazards and green locations over-laid, the ability to move position with a touch to see distances from various spots on the hole, aerial imagery, detailed stats tracking and graphing, and more.
Smartphone Golf GPS Apps
There are a number of golf GPS apps on the market for iPhone and Android operating system phones. These provide much of the same functionality that you get with a handheld, on a device you may already own. Downsides for the apps include the fact that your smartphone is not waterproof and may get damaged in wet conditions, while the dedicated handheld devices are usually completely waterproof and built to take a beating. Battery life can be an issue with smartphone apps as well, since the GPS capability goes through battery. I find however that the latest apps do a good job of power management and easily last a round if you start with a near-full charge.
If you're interested in more details on the apps, see my guide to the five best golf GPS apps. They all provide accurate distance to the front, back, and center of the green, nice hole maps and aerial views, and other basic information. The key with apps is finding the one that has the mix of features that are important to you. I like the Golfshot app, for example, because it has a terrific shot stats tracking and graphing feature and it's easy to input stats while you're out on the course.