Contributor: Editor Avec Mobile 　 Holux M-241 GPS Receiver: Review GPS is a technology of many faces. Once a GPS device is ready to pick up satellite signals, it can calculate your exact position anywhere on earth, except indoors. This is information can be used in a variety of ways as the Holux M-241 demonstrates. The Holux M-241 GPS receiver is only the size of an old-style film roll, but it provides three useful functions. It can save the route you have traveled and synchronize the location information with photos taken along the route. It can provide GPS positioning data for a navigation application on a mobile device, or it can be used as a speedometer and odometer. The Holux M-241 looks very much like a roll of Kodak film. Remember the days when photos had to be taken to a lab? And you had to pay for being able to see your photos? Fortunately, it's history. Anyway, the M-241 is about the size of a film roll. The unit is not waterproof, but the two buttons are rubber-covered. The tiny screen displays large, readable characters. The display has a backlight, but you have to push the menu button to switch it on, which opens the menu as well. The unit is powered by one AA size battery. We used rechargeable batteries without problems. Often, a dedicated GPS device is a problematic to carry because you have to hold it in the hand. The Holux M-241 has a small, but important feature – it comes with a lanyard. Excellent detail, because you can free your hands and let the GPS unit hang around the neck. Let's take a closer look at all three main features of the product: track logging (geotagging), GPS receiver for mobile devices, and speedometer/odometer. 　 How Geotagging Works - with Any Digital Camera With a GPS position tracker and a digital camera – also a camera phone will do – you can record your travel route. This is what you need to do: 1. Make sure the time on your camera is correct. The camera automatically records time in the header (EXIF) data of each image. 2. Switch on your GPS unit before you start snapping photos. 3. Take pictures on your camera as you normally do. Make sure the GPS device can receive satellite signals. 4. Copy pictures from your camera or phone to a PC. 5. Transfer the tracks recorded by the GPS unit to your PC. Use the included Holux PC software to mark the photos to their locations on the track. 6. Use an application, such as Google Earth to synchronize the track information and photos, and display them on a map. 　 1. Holux M-241 as a Track Recorder (Geotagging Device) The tiny display is one of the best features of the Holux M-241. It took us only a few seconds to figure out how to turn on the recording mode and start saving track coordinates. The display is also helpful because you can make sure that the unit is receiving GPS signals. The device itself worked really well as a track recorder. It was easy to use – push a button to start recording and push the same button to stop it. After finding GPS satellites, the M-241 kept itself locked into the signals. We posted our photos to the free Locr service that displayed the pictures on a shared map.  The sad thing with the Holux M-241 as a geotagging device is the included PC software and documentation. When you want to transfer the track data from the device to the PC and sync your photos with your travel route, you are on your own. You have to figure out how the oddly designed PC software works and how to upload your tracks and photos to Google Earth. Next time you do it, the process is easier, but still far, faraway from smooth. It requires medium-to-advanced computing skills. We uploaded our tracks and photos to Google Earth as an KML file.   2. Holux M-241 as an GPS Receiver for a Mobile Device If you own a mobile phone where you can download maps and a navigation application, like Amaze GPS, Nokia Maps, or Wayfinder, but your phone came without GPS, you need an external receiver that can be connected to the phone via Bluetooth. That's exactly what the Holux M-241 can do for you – turn your phone into a satellite navigator. After the M-241 received signals from GPS satellites, we could pair (or bond) our smartphone with the device. Tip: If your mobile phone is asking for a passcode or key when you are trying to connect to the M-241, the code is 0000 (four zeros). We couldn't find the information from the documentation. Anyhow, that's all there is to it. After pairing, it was easy and reliable to use the M-241 as the GPS receiver for a smartphone. Because of its status display, shape, lanyard, and ease-of-use, we regard the Holux M-241 as one of the best Bluetooth GPS receivers for mobile devices we have tried out so far. 　 3. Holux M-241 as a Speedometer and Odometer The device is small, shaped like a roll of film, which makes it is easy to hold in the hand while jogging or hiking. The product also comes with a lanyard for wearing it around the neck. This method allows for good GPS signal reception, but the unit tends to swing below the face.  Using the M-241 for measuring speed, distance and time was simple. We only had to push a button to rotate through the speed, distance, coordinates, and time displays. What we liked about the Holux M-241 GPS tracking device - Reliable, easy-to-use GPS receiver that can provide location information to mobile phones via Bluetooth. - The tiny display on the device was a welcomed feature for ease-of-use. It made it possible to know what was going on in the device, reducing frustration when unsure if GPS signals are being received. - The device can be used for all of its three main functions (track recorder, GPS receiver, speedometer/odometer) simultaneously. 　 http://www.avecmobile.com/index.php?id=1128