I am a Nikon DSLR user. And since I travel quite frequently I want a GPS device to geotag my photos. A GPS is handy not just for inserting the photo coordinates. But especially since dreamstime has a Geo-location link, when you submit the photo it will show it's shooting position on the map or satellite imagery, providing of course that the photo has GPS coordinates in the metadata. And it is extremely useful to know where exactly did you take a certain picture in order to submit an accurate description of that photo.
Personally, I don't understand why GPS is so scarcely available in the DSLR bodies. For instance, Canon offers just the full frame 6D with built in GPS while on the Nikon side only the D5300 cropped sensor body has it (I don't know the situation for Sony or others). Now, why those particular models and not more, or all of them have this option is beyond my comprehension. My opinion is that in today's interconnected world a GPS function should be as ubiquitous as the ability to make movies with your camera. Most probably we'll get there someday but for now it seems that the marketing minds work in mysterious ways.
Anyway, for the Nikon bodies that don't have this function built in, there is a separate GPS unit offered by Nikon. But besides the fact that is insanely expensive for what it actually is, it has another disadvantage. You have to mount it on the flash shoe and to connect it with a cable to the body. If you want to use the flash while using the GPS unit you have to take it out from the flash shoe and at best to wrap it along with the cable around the lens. Until recently, I have used an alternative Chinese unit from Micnova, which has the same functioning principle as the Nikon offering (and which, certainly, is far cheaper). It worked perfectly until I managed to damage the connecting cable. And I couldn't find either a replacing cable or another GPS unit. Which turned out to be quite good since I have found a better solution. Searching the web I have found the website of Aokatec company - also Chinese, of course :) The company website
Unfortunately (for other DSLR brands), they make GPS units just for Nikon bodies. What is cool about their products is that the unit has the connector directly mounted on it without the need for any cable. You mount the GPS unit directly on the camera and it stays better than anything else. In fact it is so small that you hardly notice you have something connected to the camera. They have separate models with the different connectors for all the Nikon DSLRs.
Since the price was affordable I have decided to "risk" and buy one. You can purchase directly from their website but I have preferred eBay since I have found a seller in Hong Kong which sold me the unit along with the shipping costs to Romania for 45$. It arrived in a week, I have tested it and I can say it is a great product. It works perfectly and like I said before it is very small. It has also a faster GPS satellite signal acquiring than the previous unit I have used. And once you allow the initial 30 seconds "cold start" as they say, once you keep it connected to the camera the GPS signal is virtually acquired instantly all the time even if you turn off the camera.
So there you have it, in case you need a cheap and cool geotagging solution for your Nikons. Here are also some photos made using this device.