Guys, if you just want UK mapping then don't pay £20, £30 or more for tom tom, copilot or similar .
Try Waze... it's free

and works equally well. Waze gives great traffic reviews ( perhaps for when you are in the car rather than on the GS?) but also gives speed camera alerts .
(Steve H I too like Navfree but it suffers from Adverts )
Look here ;
http://www.waze.com
You may not have heard of Waze , but they are well funded and have 7 million users on IOS and Android.
Another alternative is to invest in an iPhone 5 which has it all built in to IOS 6 .........