Christopher Wellons over at null program has a nifty post on rendering fractals in Emacs. He shows how to draw and display fractal using Emacs lisp. I didn't know you could do stuff like that. The Elisp writes the image in Netpbm format and then switches the buffer to
image-mode. The code is surprisingly simple.
None of this is going to change your life, probably, but it is a lot of fun and it shows off the amazing versatility of Emacs. Head on over and take a look just for fun. You might also want to experiment a bit to see what pretty pictures you can come up with.