Check out the wiki, USB Host mode on the N800 using OS 2008..Very easy howto.. Its so much easier than modding your own usb cable..
I followed the directions from 2nd part,Another Simple Method of setting the N8X0 with OS2008 to host mode - Status Bar Switch..
Freakin Rocks... Becareful with your adapt/usb cable plugged into nokia,
I've come close to killing the usb port...