Check out this tutorial for etching images in copper onto circuit boards!
I suspect that there’s a lot more that can be done with the plates than meets the eye. Things that immediately come to mind are a variety of chemical tarnishings, using it as a printing plate on paper, several possibilities for magnetically aligning ferrous powders (think chaotically textured relief prints!), or any combination of the above. There’s got to be more, what did I miss?
Read instructions at Instructables
Via MAKE Blog