Driven by the widespread adoption of iPhone OS 3.0 on the iPhone 3G and the successful launch of the iPhone 3GS that includes a digital compass along with the GPS system, all major players are now proposing their route planners to iPhone users.

Most apps will provide voice-guide and 3D on-screen navigation with automatic rerouting incase users miss a turn.

GPS device maker TomTom is being developed with the help of Apple engineers. It will be sold alongside a TomTom car kit accessory, which enhances the iPhone’s GPS signal through its dock connector thanks to third-party accessory support built into the iPhone SDK 3.0. The kit also charges the iPhone, includes a built-in loud speaker for spoken turn-by-turn directions, and comes equipped with a microphone for hands-free calling. TomTom hasn’t announced the pricing for either the software or the car kit.

The AT&T Navigator is already available in the U.S. App Store, and is compatible with the iPhone 3G and iPhone 3G S running iPhone OS 3.0. A monthly subscription fee  ($9.95) will cover automatic map updates that will be downloaded to the iPhone and real-time traffic updates.

Navigon released its own MobileNavigator with European maps. The software is priced £54.99 and features built-in 2D and 3D maps of Europe, allowing it to function without a wireless connection.