If you don't have a map app on your smartphone, download Google Maps. Now. The free mapping app gets more powerful and indispensable with every update. It can predict your location using GPS or cell tower triangulation, and use that fix to find businesses near you and calculate directions for driving, walking, even taking public transit. You'll be able to click to call locations, and send details to friends via text.
Map layers include traffic flows and points of interest on Wikipedia as you switch between satellite and map views. If you're into Google Latitude, a social-networking geolocation feature, you'll also be able to track friends. The latest version of the map app can sync your favorite places on the phone and online, so you can revisit a spot on the map no matter where you are in real life. The possibilities for growing Google Maps for Mobile are endless, but we'd settle for adding voice searches next.