Reverse image search as serendipity machine.
For an explanation of how this works, see "Visually Similar" Volume 1 of 5. I really love the last two sets of "Visually Similar" so I'm going to do them both with large thumbnails.
I was searching for a source for this:
And I found these:
And the timeless Christy Turlington:
A better version of Eva Herzigova by Rankin: