XnView has a handy feature called “Find Similar Files”.  It actually means files, not just images, although it’s not well-designed for non-image files. continued …

I’ve often wondered how other people handle it; the hours it takes to research, record, file, surf around to see what everyone else is doing, write a blog, or several of them, keep up a mad social-networking schedule with six hundred and fifty of your new best friends and make a living using a computer as well. continued …