The TomTom iPhone GPS hardware and software combination may have been featured by Apple at this year's WWDC, however Navigon has already hit the marketplace. Navigon is a full-featured turn-by-turn GPS navigation system for iPhone.
Navigon's MobileNavigator North America is available now on the Apple App Store. Although the price sounds steep at $69.99 (increasing to $99.99 on August 16th), this is a one-time cost with no ongoing subscription fees. In contrast, AT&T Navigator is a free download, but incurs a monthly fee of $9.95.