Every digital photo has metadata. Below are some websites that allow you to read this metadata. In many cases, if a persons GPS is turned when the photo is taken, you can find the LON/LAT.
Geoimgr
Metapicz
ReadEXIFData
GoogleInside Search
Now you can explore the web in an entirely new way by beginning your Google search with an image. Learn more about images on the web and your own photos.