You really need to investigate NavTraffic before you comment on it. It really is amazing. It's only available in about 30 cities right now, but the list is constantly growing. It uses information from several sources such as the police, DOT, etc and also uses flow sensors in the freeways to report the speed traffic is moving. It is continously updating and is as current as any traffic report you will ever get. Sometimes even more so. It pops up trouble spots from accidents, construction, heavy traffic, just about anything that disrupts the normal flow of traffic. The Z1 even displays the speed the traffic is moving at in slow spots. The icons for trouble spots are automatically populated to the navigation map where you can display just exactly what the problem is. The Z1 will even automatically reroute you around them. And if you already have XM radio, it's about $4 a month. The first thing my wife does when she heads to work in the morning is calculate her route and check the NavTraffic along the way. No more having to listen to the radio to find the trouble spots.
You can find out more about it here:
http://www.xmradio.com/xmnavtraffic/about.jsp
But the proof is in the pudding. Find someone who knows how to use it. You will never make another comment like that again. It's that good.