I've started using the website http://gebweb.net/optimap/ to plan my mapping forays. I click on all the streets I want to visit (usually based on the ITO Analysis site) together with my start point and end point and it works out a route for me. I then enter the points as Favourites in my TomTom iPhone app, numbered according to the sequence the optimap site calculated, then navigate from one to another. Sadly, it's based on Google Maps! If anyone knows a better one, let me know. It's a shame the TomTom app doesn't have a file upload facility though: it's a bit tedious entering all the locations manually. I daresay there are other routing apps that do have that capability though.
Tonight's target area is Greenhithe and Stone.