When creative types are not downloading vector art from inexpensive stock image sites and pawning it off to be their own logo, they are constantly taking in millions of advertising images and ideas that then get filed in the back of their brain. Every now and then we realize in a brainstorming stage of a project that something just seems oh so familiar about what we are looking at. We've all done it, admit it. But some of us never let it get past that stage. You'll be amazed at what does. Check out this collection of ads created by many different agencies but based on similar idea or image. You may want to wait until Friday afternoon to click though since you can easily waste a couple hours of your day viewing them all.