I would agree with the Smartphone based solution. Without pushing TomTom software on the phone specifically .........
..... I would use a larger screen model like Samsung S3, Asus Nexus7
Interesting and helpful post, to clarify (and As Alistair implies) The two phones mentioned are Android devices and Tom Ton is currently not available for them, - it has been promised "This Summer" still waiting, so I will be using Co-Pilot on my 6 week Spanish Jaunt next week.