So here is a video showing how to use a .py file off the net in XSI
*Note that every .py file is hand made and the maker can place his user menu where ever he wants*
Anyway... hope this video helps you out Mario :D
P.S this .py said it was made for 32 bit but it worked perfectly well on my 64 bit xsi... Win.
*By the way, this is a great little tool Booyabase*