Geotagging photos, putting the GPS position information where the photo was taken in the EXIF metadata, has been around for years. Until recently, it was a process reserved for geeks who found some way to grab and store GPS location (a laptop hooked to a GPS or a GPS data logger), then take that information, generally run it through a software program that would match time information from the GPS and from the photo, and put the GPS info into the metadata.

Recently, some cameras have come with the ability to attach a GPS, and even have built in GPS’s, but not very many people are buying a camera just to geotag photos. However, a very large number of people are using their phone’s camera to take and share pictures now. For instance, the iPhone.

What many may not know, all iPhone photos are geotagged. You can turn that off, but it’s not something you’d do ordinarily. To turn it off, you need to go into settings, and turn off "Location Services". That’ll turn off the GPS and the mobile triangulation, but otherwise, every photo you take will have the last known GPS coordinates stamped on it.

This came to light again today when one of my favorite gadget stores, thinkgeek, posted a Top Secret photo of their new office. Just a simple interior shot. But, they posted it directly to Flickr, and it had the location right there in the photo. Oops, so much for that Top Secret new location!

Why would you care? Well, you’re taking pictures at your house, or your friends house, and posting them to Flickr. Do you really want everyone knowing where you live, or where your friends live? Within 20 feet? For some people, it’s no big deal, but for others, well, some amount of privacy is a good thing.

I’d been thinking about this for a while. I take a lot of pictures at my house, but don’t generally want people knowing where I live, you just never know who’ll use that information, or just "come visit". I try hard to remember to turn off location services before taking pictures with my phone at home, but I’m likely to slip up eventually. That’s when another service comes in handy. When posting to Flickr or other public sites, I user services like TwitPic or Posterous, (and even the cool iPhone app ShakeItPhoto) where your EXIF is stripped before posting. Some might find that annoying, but it has the side benefit of removing the photos location. It might be nice to have that as an option eventually, but right now it’s a great way to go for me. I don’t send photos directly to Flickr from my iPhone, only through one of these services. Of course, Flickr just announced a new feature to tweet about uploaded photos. That’s great, but be careful out there if you want your location information private!

Now another bit of party etiquette I’ll need to have to work on with guests, if you want to take pictures with your phone, that’s fine but please turn off location services first.