Geotagging has grown into a popular complement of digital photography, as it allows you to automatically mark your digital photos with the time and location of the shot. Geotagging information can be stored with your EXIF data. (The EXIF data stores information about how the photograph was shot.)

Some cameras have a built-in GPS unit, which allows the geotagging to be an automatic process. When using a camera without a GPS unit included with the camera, you'll have to add the location data to the image data later, either as you're shooting the photo or after downloading the photos to a computer, using geotagging software.

These tips should help with your geotagging efforts.

• Geotagging your photos has a variety of benefits, especially if you upload your photos to a photo storage Web site. For example, with some sites, if you upload a geotagged photo, the Web site will allow you to link the photo to an online map that shows the exact location of the photographed item. Or, if you are scouting good photography locations and shooting some sample photographs, by using geotagging information, you can find the exact location again later that provided what you thought would be the best angles for the photo. This can be especially helpful if you're shooting in remote locations.
• Some GPS receivers can work as geotagging units by attaching directly to the hot shoe of a DSLR camera. If you want to make collecting geotagging data fully automated and easy, you'll want to purchase this type of equipment, or you'll want to have a GPS unit built into the camera.
• Another piece of geotagging equipment allows you to insert your memory card into the geotagging equipment, which then writes the geotagging information to each photo's EXIF data. If you're interested in this type of equipment, check with your camera store for something that's compatible with your camera equipment and your memory card. You don't want to spend the money on this geotagging equipment, only to find out later that it's not compatible with your camera hardware.

• If you don't mind doing some extra work, however, you can make geotagging less expensive by using hardware you already own, such as a GPS unit. GPS units can be stand-alone pieces of hardware, or some cell phones even contain GPS units. To use a GPS unit not attached to your camera, place the GPS receiver in tracking mode. As you snap photos, track each location in the GPS unit. Then, as you download the photos later, you'll have to manually enter the GPS coordinates into the EXIF data, using an image editing program or geotagging software. This requires quite a bit of time, so be sure that you really want to use geotagging before you invest the time in this process.
• Finally, if you're planning to purchase a new digital camera anyway, consider buying one with a built-in GPS unit, such as the Sony SLT-A55 DSLR model pictured here. As you shoot each photo, the camera's GPS unit includes the GPS coordinates in the EXIF data of each photo automatically. This is the easiest way to handle geotagging your photos. Keep in mind that cameras with built-in GPS will be a bit more expensive than models with similar photographic features, so make sure that your budget can handle the expense. In addition, running a GPS unit in your camera is going to cause the camera to drain its battery much more quickly than when the GPS unit is turned off, so only turn on the GPS during the times that you really need to use it. You also may want to invest in a second battery with your GPS-enabled camera, just to protect against a dead battery while you're shooting photos in a remote area.