Living in overcrowded Northern NJ, traffic is a big factor deciding how I'll get into Manhattan or just about anywhere around here.
Google Maps now uses the data it collects via cell phones with GPS running gm to build up to date traffic data. For example, you can now see cross streets in Manhattan. RIM recently purchased DASH for similar technology.
Now I can see all the roads that go where I need to be are clogged and I'm less frustrated sitting in my car wondering if I should have taken a different route