Originally posted by: InflatableBuddha
You could write an entire paper on the "Myspace angle", or the types of photos people post in Craigslist personals...I'm sure it differs between "Casual Encounters" vs. M4W, W4M, Strictly Platonic, etc.
Photoshopping would be another umbrella concept entirely, and the OP would have to pick a sub-category, such as photo-editing supermodels for magazines.