I must warn you that is isn't working like a charm here. It's slow and some windows don't render properly, nevertheless here you go:

Installed to HD
I installed the drivers from ati.com
pressed ctrl+alt+backspace to get out X
did 'aticonfig --initial'
ran startx
On the usb version there is a file /bt3/optional/cubez.lzm
cd to it's directory and run 'lzm2dir cubez.lzm /' this will extract it to /
now edit your /etc/X11/xorg.conf and add:
Section "Extensions"
Option "Composite"

Restart X again, it should now work

Big question now: how to properly remove it again, changing between windows is real slow. The benchmark just dropped from 250 to 15 fps