Unless the place and time is important to your image capture, and the context within which you wish to use it - TURN IT OFF!
If you decide to remove this data (Exif tag) later - such as before publishing on your blog - you may need specialist software to remove it.
GPS = Global Positioning System
Exif = Exchangeable image file format
How to turn GPS off
Go to your iPhone's home screen and click on the settings icon
Find 'Privacy' and click on it
Next click on 'Location Services'
Note: you can at this stage switch GPS off completely.
If you do you'll also disable maps, compass etc
Alternatively you can turn the GPS of individual apps off using each individual on/off slider button.
|Here the camera's GPS is switched off|
|Here it's left on|
The top example is the safer alternative