Global Positioning System add-ons for smart phones and PDAs are nothing new. But a GPS clip-on? That's what the super-tiny Garmin Mobile 10 claims to be.

Garmin's Mobile 10 is a compact GPS receiver that transmits location information via Bluetooth to Garmin Mobile XT mapping software that you install on a supported smartphone, PDA, or notebook.

The Garmin Mobile 10's GPS receiver locates your position, which is displayed on the mapping software. The software calculates a route to your desired destination(s). You can receive turn-by-turn directions via voice prompts, delivered using your device's speaker. And you can visually follow your route on the mapping software. Recently, we tested the Garmin Mobile 10 with a Palm Treo 650 and we recommend it - with some caveats.

See also Palm Treo 680 review

Convenient to carry

The Garmin Mobile 10 weighs only around 60g and measures 18x42x77mm. It's so small you can take it anywhere. You could also lose it anywhere, but c'est la vie.

The aforementioned clip, which is removable, is a nice touch. You can clip the Garmin Mobile 10 on to your belt and receive directions while walking. Or you could clip the GPS to your car's sun visor while you're driving.

Either way, the Garmin Mobile 10 is delightfully easy to take with you. And because it works with a device we already carry everywhere - my Treo 650 - the Garmin Mobile 10 is the most convenient portable GPS receiver we've seen. There's no extra bulk.

Generally good directions

We tested the Garmin Mobile 10 in San Francisco over several weeks. In most cases, the directions we received were good, but not always the most practical.

For example, in a San Francisco neighborhood we avoid using 24th Street, as it is often congested with mobile-phone-talking pedestrians dawdling on their way to digressing, double-parked delivery trucks, surly teenagers on skateboards, and the occasional Segway. But in many cases, the Garmin Mobile 10 directions had me going by way of 24th Street. Local knowledge still counts for something!

A nice price

The Garmin Mobile 10 is attractively priced. we've found it for about £170 online. If you shell out for an all-in-one portable GPS system (with more features than the Mobile 10), you'll pay more, but you'll have to carry more too.

But keep in mind that a growing number of smartphones have built-in GPS capability. In many cases, however, you must pay a monthly fee for navigation services.

A few caveats

The Garmin Mobile 10 sometimes takes several minutes to acquire a satellite signal, particularly when used in a new location. So if you hope to jump into a rental car at the airport, turn on the Mobile 10 and instantly get driving directions, you'll be disappointed.

When you're following a route the Mobile 10 has devised, you'll get voice prompts on your smartphone, PDA, or laptop. But the prompts are not as detailed as those you'd get in higher-end GPS devices. For instance, a Garmin Nuvi will tell you to "turn right on Market Street" but the Garmin Mobile 10 only tells you to "turn right".

Get the latest satnav reviews here

Garmin Mobile 10: Specs

  • rechargeable and removable lithium-ion battery with 22 hours (typical use) battery life
  • power supply
  • high-sensitivity receiver
  • compatible with PDA, smartphone compatible
  • connects to laptop, Pocket PC, Palm or compatible smartphone with Bluetooth wireless technology (serial port profile)
  • navigation software
  • street maps, including Points of Interest (POIs)
  • 4000 waypoints
  • voice prompts
  • 3D map view
  • auto re-route (fast off-route and detour recalculation)
  • rechargeable and removable lithium-ion battery with 22 hours (typical use) battery life
  • power supply
  • high-sensitivity receiver
  • compatible with PDA, smartphone compatible
  • connects to laptop, Pocket PC, Palm or compatible smartphone with Bluetooth wireless technology (serial port profile)
  • navigation software
  • street maps, including Points of Interest (POIs)
  • 4000 waypoints
  • voice prompts
  • 3D map view
  • auto re-route (fast off-route and detour recalculation)

OUR VERDICT

If you travel frequently, often need directions, are on a budget, and already carry a Treo or other Bluetooth-enabled device, the Garmin Mobile 10 is an ideal GPS option. It's small, inexpensive, and works well for the most part. But don't expect directions as practical as those you'd get from a local.

Find the best price