If you are curious about exif data whenever you see a photograph this little tool will certainly come in handy. It is an extension for Google Chrome only which you just add to your Chrome browser. It is very easy to use as whenever you come across an image: hoover over it, right click and choose "Show exif data" from the popup context menu.
Get it here: chrome.google.com/webstore/detail/exif-viewer-pro/mmbhfeiddhndihdjeganjggkmjapkffm/related?hl=en
p.s.
It is totally free, has no adware, no spyware or other nasties.