Here are however some ideas I had, that probably are, all in all, just as pointless:
- Encryption by colour:
-- You create an image like above from a private key.
-- You "divide" this picture into two or more images, with their hues being randomly split and delete the original image
-- Only if you have all images and stack them, somehow adding their colours (the easiest probably would be to divide it into R-G-B), you can create the original "private key" image
-- You could probably generate a private key by stacking actual images, for example from your family, or whatever (maybe of your fingerprint? But that's a different story).
- Using the address to create fractal art/vectorbased images:
-- I don't know how you would "reverse engineer" the address from there, but maybe it looks pretty
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)