Some people may not be aware that photos taken with the iPhone camera have the GPS coordinates of your location embedded in the EXIF metadata of the file. This means that when you post the picture online or send it to someone, you’re letting them know where you were at a certain place and time. If you’re ok with that then there’s no problem. But if you want to disable it, it’s pretty simple.
The procedure is basically the same as the one I described in this post about enabling Facebook Places. The difference is that once you’re in Location Services you’ll want to make sure “Camera” is disabled. Photos taken from that point on won’t have GPS embedded in their metadata. If you want to turn it back on, just set Camera to “enabled” in Location Services.