Here you go:

http://khan.thpinfo.com/~thp/tmp/pydance-maemo.tgz

What you need to get it running:

sudo gainroot
apt-get install python-pygame

Then copy the downloaded file to your device and do:

cd MyDocs
tar xzvf pydance-maemo.tgz
cd pydance-1.1.0
python pydance.py

The keyboard bindings are as follows: Enter and Backspace to navigate the menus, and your dance pad is the square with "q" in the upper left corner and "c" in the lower right corner (i.e. "a" is left, "w" is up, "x" is down and "d" is right).

Only one song included (from the website). You can put more songs into "songs/", but be sure to decode the .ogg file to .wav and change the filename in the .dance file, because pygame (at least on the N810, and I guess also on the N900) does not support ogg :/

Enjoy. If people like it, I might do a proper .deb later and upload to Extras-Devel. But now back to some serious learning...