I've got '
SmartNav'. Great bit of kit, basically a dash mounted button is pressed and the independent hands free GSM unit connects to a call centre. You tell the girly / laddie where you want to go (this can be town, street, post-code, business name, even supermarket's, cash machines etc) and the route is downloaded in seconds to the in-car sat-nav unit. Synthesised voice directions coupled with (optional but recommmended) guidance on a screen fitted to the dash send you on your way.
Other good points? It's run by Trafficmaster so it checks on traffic conditions before and during the route, amending it on the way if required. If you break down, the call centre will contact your roadside assistance organisation and tell them exactly where you are. There are also options for speed camera location alerts, and
RAC Trackstar (car nicked? They can tell plod where it is).
Bad points? Cost - retails around £649 including fitting, and subscriptions work out at about £30 a month for nav, speed camera, and trackstar services (if you take all three).