Comments section facebook and members avitar intergration

Hi

I am looking for facebook signin to be added to my PPH comments section.
Signed in members should also have their avitar visible/added when commenting.
At the moment the comments section is just a simple text interface with the signed in members name only visible.
Eg

http://www.pixoto.com/stock/new-arrivals?search=all#/images-photography/people/portraits-of-women/gipsy-6673409052246016?&_suid=1374462065674049725336424901434