Google on Wednesday introduced a beta version of Google Maps Navigation, an Internet-connected navigation service for mobile devices that offers turn-by-turn, GPS-guided travel directions. Google said its new Google Maps Navigation product will provide real-time, turn-by-turn directions directly within cell phones that are based on the new version of its Android software. The navigation product, which features speech recognition and a visual display that incorporates Google’s online archive of street photographs, marks the latest step by Google to challenge Apple Inc’s (AAPL.O) iPhone and Microsoft Corp’s (MSFT.O) Windows Mobile software with its Android smartphone software.

Google Maps Navigation could have a huge impact on the overall smartphone market as well. It may be the first killer app for Android, a must-have feature that lures consumers–particularly commutergoogle gpss seeking a smartphone with good nav features–away from the iPhone.