The Collaborative International Dictionary of English v.0.48:

Photo \Pho"to\ (f[=o]"t[-o]), n.; pl. Photos (f[=o]"t[-o]z).
   A contraction of Photograph. [Colloq.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Photo- \Pho"to-\ (f[=o]"t[-o]-).
   A combining form from Gr. fw^s, fwto`s, light; as,
   photography, phototype, photometer.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "photo":
   3-D, Telephoto, Wirephoto, aerial photograph,
   black-and-white photograph, candid photograph, cheesecake,
   chronophotograph, color photograph, color print, diapositive,
   heliochrome, heliograph, montage, mug, mug shot, panchromatic,
   photoactive, photobiography, photochronograph, photogenic,
   photograph, photographic, photomap, photomicrograph, photomontage,
   photomural, photosensitive, picture, pinup, portrait, shoot, shot,
   slide, snap, snapshot, still, still photograph, telephoto,
   telephotograph, telephotographic, three-dimensional, tintype,
   transparency