Wii homebrew alert! Math fans would love this one. Even just people who like psychedelically pretty stuff. If you know the Mandelbrot set, then you'll get what we mean. It's basically a program that creates fractals.

Here are the developer's notes:

You can load it with Front SD ELF Loader, I haven't tried the other possibilities but they should work.
A - zoom
control pad - move
L,R - change palette
X,Y - change number of iterations - use to get more details
start + Z - resets to loader