This looks like a very interesting Google Maps offering; quoted from http://www.google.com/gmm/index.html
Take the power of Google Maps with you on your mobile phone.
New! Google Maps with My Location (beta)
Real-time traffic — See where the congestion is, and estimate delays in over 30 major US metropolitan areas.
Detailed directions — Whether you plan to walk or drive, your route is displayed on the map itself, together with step-by-step directions.
Integrated search results — Local business locations and contact information appear all in one place, integrated on your map.
Easily movable maps — Interactive maps let you zoom in or out, and move in all directions so you can orient yourself visually.
Satellite imagery — Get a bird's eye view of your desired location. (It's like you're there, we swear.)
