There's no shortage of golf gadgets in the world, but these three are worth a special look. Two are based on Android handheld computers (PDAs) while the other clips to your clothing and talks to you. If that sounds all techie and horrible and a total anathema to getting away from it all on the golf course, worry not, these devices are unobtrusive and are here to help. They're like tiny robot caddies.

Fundamentally, the handhelds let you keep score electronically while also measuring distances (in yards or metres). They are legal in all competitions because they are fundamentally measuring devices. This is different to smartphone apps which are banned in competition because they also can provide unfair assistance such as weather information, wind and slope details. They also have far superior battery lives and won't drain your phone.

Common handheld features

Both handhelds keep score - you just jab the number of strokes you took. However, they also allow you to record how many putts you made and whether you drove off left or right of the fairway. Both cater for up to four players at a time.

You don't have to program them either - just turn them on in the car park and by the time you hit the first tee they'll know exactly which hole you're playing on at which golf club in the world. If for a reason it gets a location a little wrong (because two tees are very close to each other or that a single tee is used for two separate holes) it's simple to manually adjust which hole you're supposed to be playing. As you walk round the course they will automatically know when to focus on the green or the next tee.

They'll account for handicaps and keep track of whether you're using a Stroke play or Stableford scoring system.

They both show an illustration of each hole and provide the distance from where you are to where you hit the ball. Both also allow you to jab a point on the map and set a target on the fairway to lay up to: you will then be given the distance to that target and then on to the green.

On both models you can adjust where the pin has been positioned on the green. The view of the green also changes automatically depending on your angle of approach.

Both can measure the distance of individual shots at the click of a button.

Both are weatherproof (not fully water proof) and can be viewed in direct sunlight.

You can also preview a course before you play it.

Garmin Approach G6 ($330ish)

It may be a little less refined than the GolfBuddy Platinum but the G6, with its 2.6-inch screen, is a useful piece of kit. Basic functions involve showing a representation of either an entire hole or just the green (all distances are to the middle of the green by default but you can drag and drop the pin as required) and you can pick a target along the fairway to aim for too (it will tell you the distance to the target and from the target to the green. It will also display the distances to any hazards.

Measuring the distance of a shot is simply a case of holding the measure button to set a mark and walking to your ball after hitting it. Uniquely, you can then add that distance to each of your club's average distance and build up a very accurate average measurement for each club that you have. If you've got some obscure clubs you can easily add more and rename any existing ones.

Included accessories are limited - there is a wall charger and holder with carabiner. The battery lasts for around 15 hours.

The two buttons make it facile to use although the slightly smaller screen and chunkier graphics weren't quite as pretty as those seen on the Platinum. That said, the functional nature may prove attractive to technophobes who prefer a simpler layout that focuses on basic information and intuitive ease of use.

Unlike the platinum it also caters specially for Match Play and Skins scoring methods.

We had very few problems when testing it although it did freeze up when measuring the distance of some shots sometimes: only an annoyance in that a great tee-off was only registering 28m, but it didn't happen too often.

Saved information is simple to view later on - two web page files are stored on the device and can be accessed just by plugging it into a computer. However, only basic score information is displayed although you are reminded how many fairways were hit from your drive plus how many greens were hit in regulation and how many putts you took in total.

The other page keeps track of your club averages. However, due to a mistake in selecting the wrong course on one occasion my average drive is now listed at almost six million metres and I can't change it without resetting all its scores. Nonetheless, it's simple to use and simple to access.

Course updates are for life (there are some 30,000 global courses at present and over 1000 of those are in Australia). At $330 it's a reasonable price and generally cheaper than the more powerful GolfBuddy World Platinum although the wild price fluctuations of that might change things. It feels more basic and functional than the Platinum and this could be attractive if you point blank hate technology. If you like the idea of measuring the average distance for all of your clubs, prefer pressing buttons to fiddling with the screen and aren't too fussed about keeping track of (and analysing) your historical round statistics, then it could make for a more attractive choice.

GolfBuddy World Platinum ($220ish to $449ish)

The Platinum has a slightly-larger, 3-inch screen with a higher resolution and an 18-hour battery life. Having 50-channels makes it fast to lock on to satellites but it wasn't noticeably more accurate than its competitors. Some 40,000 courses are loaded onto the included microSD card and updates are also for life. On the one hand, more fairway information is visible in terms of colour schemes, however, you'll sometimes need to jab the Targets button to see how far each hazard is whereas the G6 displays everything at once. While more information can be displayed it's not always correct: a path was listed as a creek on one of our holes, although it was better having it there than not at all.

Setting a mark involves tapping the side button but you can't record which club was used to strike the ball with. Nonetheless, you can easily set marks wherever the ball lands. When recording your score you can note whether you hit a bunker or not.

Where the Platinum pulls away is with its computer integration: a computer program manages the information and device updates. Each round provides more information than simply numbers; there are graphs for how often you hit the fairway or the 'Green in Regulation' plus your number of putts and putting average. It's all very well laid out and more useful than the Garmin in this regard.

Accessories include two flavours of clip case and a car charger. It's a more refined product than the Garmin but it's pricey at $449. However, a bit of savvy internet shopping means it can be had for just $220 from US-based suppliers and the global nature of the product means you'll still get all of the courses. You'll lose local support buying from overseas but not paying the 100 per cent Nice Beaches Tax balloons the value proposition.

Ultimately, if you want a fully-featured, easy to use map tool and score card just for the course then the Garmin is probably your best bet. However, if you don't mind more-fiddly operations and want to track your performance on the computer (and you can find it cheap) then the Platinum has the edge.

Missing features

There is some serious power in the units. With that in mind it shouldn't be too hard to record everything you do on a course just by hitting the ball, walking to the ball and telling the device which club you used. In doing this you wouldn't even need to type in your score. You'd also be able to track your round history over time and see where you are having consistent problems on a course. The stat tracking would be out of this world. How hard can it be?

Golfbuddy Voice ($120ish to $240ish)

The small, square, golf-ball-sized, 30-gram Voice is a different beast altogether. The small LCD display carries minimal information although it's still able to provide a small line-diagram of each hole. This zooms into the green where appropriate and even rotates the diagram depending on you angle of approach.

Its basic function means you press the button and it tells you the distance to the green using clear, femal voice. It can't be overstated how quickly you come to rely on this. There's no more scanning around for course distance markers or working out which club to use based on guess work and iffy trigonometry (or Imperial/Metric conversions in some countries). With one of these clipped to your shirt or hat you now will always know the exact distance to the green - just by pushing a button and listening. You can also choose the front, middle or back of the green if you want to be a smidge more accurate on your approach play.

That's not all; with a few extra button pushes - which you'll have to learn as they're not that intuitive - you can also set marks and measure the distances of your shots.

The downside is that the small size means that it's easily lost. But once you lose it you'll quickly realise how much you relied upon it and you'll seriously miss it not being there.

Naturally its size limits its functionality and it can't keep score or provide course maps like the handhelds.

Value is another concern. In Australia it costs $240 which might sound reasonable. However, in the US (and online in Australia from the likes of eBay) it can be had for literally half that.

Nonetheless, this isn't just a great golf gadget it's a great gadget. It's pure innovation, simple to operate and will do the job for golfers of all ages forever.

Basically, if you play golf then you need one of these, it's just as simple as that.