Guardian: Google offers live traffic maps for mobiles -- a killer app?

Most people don't have satnav and most people do have a mobile , with an increasing number able to access the web. So if you get caught in a jam, do you a) walk to the nearest shop by a sat nav and set it up in your car, or b) google it? As for safety, stupid people can't be stopped, but if you have a passenger, or you are at a standstill, you will be OK.