Sprixi was a site using creative commons photos and allowing for better labelling and sorting of them.  I put in a lot of effort tagging morris-related photos with more accurate descriptions and was rather frustrated when the site vanished about a year ago.

It's now back - http://www.sprixi.com/ - but frustratingly you now can't use it without paying $5  a month.  I could have three free months as I was a previous user, but I'd still have to set up a regular payment by Paypal to claim my three months so I shan't bother.

My interest wasn't so much in using the pictures, more in sorting them.

I'm not sure if the site is currently more or less useful than Google images, though I used to like the sorting mechanism which allowed you to mark photos that were wrong for your search.  I also liked the fact that all photos there were Creative Commons licensed, so you didn't have to worry about breaching anyone's copyright if you used them.