Sean Barrett wrote:
If each wikipedian took 10 pictures of the interesting things he visits, I'm sure we would not need nonfree pictures any more.
No matter how many pictures I take of the interesting things I visit, I will never take a picture of Bob Keeshan (1927-2004) -- and you will not find a free picture of him.
However, it may not be impossible to acquire one eventually. As Wikipedia gets more famous, the estates of famous people may start to dislike the fact that that person's biography has a conspicuous lack of an image, and consent to GFDL-licensing an image to fill the gap. If we fill it in with a fair use image, that removes the incentive.
-Mark