I'm a regular user of a site called irc-urls.net (sporadically NSFW), which finds images mentioned on IRC. I tried to think of some other sources of images, and Twitter came to mind. I created some scripts to automatically scan Twitter for images, and if an image is mentioned often enough, it gets added to the site. There is also an unrestricted raw feed.
I'm handling images based on a fingerprint taken from the pixel data itself, so an image with a different filename or even a sligthly different file are still regarded as the same image. Another fun feature from admin point of view is that it can guess a title for images based on the longest common substring of tweets about that image.
The site won't cure cancer, but hopefully provides another good source of fresh stuff to add to peoples' RSS feeds.