Tomtom and Google
Google has added a new feature with wich you can drag around your route. How this works is explained on this page in the movie below. Basicaly you just make your iternarary with a great interface. Very easy and much easier then doing it on your Tomtom. Added fun is that you can do it from any machine in the world.
I turned this link into this file.
This is the Google Maps to Tomtom iternerary converter
More explanation on this page