Sorry but you are wrong Tron. I have just purchased TomTom3 Maps for USA and Canada and am successfully running them on my IPAQ.
I have TomTom Navigator 3, I've installed the 3.07 updates from the TomTom site, and have installed the Florida map (about 40Mb) from the USA Map CD's.
The USA Maps are purely that. i.e. you will also need to purchase the Navigator 3 software as well.
The following is the wording on the Important Information that comes with the USA maps... "This product contains the maps of the USA for use with TomTom Navigator 3 software (not included). Please install the TomTom Navigator 3 application before installing these maps".
The TomTom GO product though can only run with the available European maps (no USA ones available). Have a look on http://www.pocketgps.co.uk for some good info on their forums about TomTom, and any other GPS system / software. Its a very good site.