With the announcement of iPhone OS 3.0, we knew that real-time, turn-by-turn navigation would soon become a reality on the iPhone. It was just a matter of when and how, and it looks like we finally got our answer on Monday.

Joining Apple onstage at the WWDC 2009 keynote, longtime GPS manufacturer TomTom unveiled its application for the iPhone, bringing maps and voice-guided directions to the smartphone. The biggest boon for drivers is the addition of the audible prompts, since the current iPhone is only able to provide text-based instructions through Google Maps. In addition, TomTom will offer a car kit for the iPhone, which includes a vehicle mount and car charger.

The TomTom app is expected to be available this summer, but as CNET’s Erica Ogg and Kent German point out, the big question is how much this will cost. Mapping and navigation software isn’t cheap, so it’ll be interesting to see where they put the pricing on this app and how it compares with Sprint Navigation on the Palm Pre. Also, I have to wonder, would Garmin have been better off going the app route instead of launching its own Nuvifone line of GPS-enabled smartphones, which has yet to see the day of light?

The most talked-about bunch of updates Apple unveiled at WWDC came from its iPhone 3.0 software upgrade, which purportedly adds 100 new features to the iPhone. Critics have long stressed the need for cut, copy, and paste features across the iPhone OS, and those features are now built in. Also, all key apps in the iPhone now feature landscape mode to maximize screen width. And in the U.S., iPhones on the AT&T network will finally feature MMS support later this summer.

Search features have also been enhanced in iPhone 3.0 with the addition of Spotlight. This will enable users to search not only their contacts, but also calendar entries, notes, e-mail, and even apps on the device.

iTunes will now allow iPhone users to purchase or rent movies directly from the device, and Apple has added parental controls that will restrict the kinds of movies, shows, and apps that children can run on the phone or iPod touch.

For Mobile Me customers, Apple will offer a service called Find My iPhone, which will locate a lost or stolen device (if it’s turned on).

As promised in a previous iPhone announcement, iPhone 3.0 includes push notification for instant messaging and other applications.

Perhaps the most exciting update for iPhone 3.0 is the addition of tethering capabilities. At last, users who are away from their Wi-Fi network will be able to use the iPhone’s cellular broadband connections to connect their laptop to the Internet. This feature will work via USB or Bluetooth, and is supported by 22 carriers in 44 countries.Unfortunately, AT&T is not one of the carriers supporting this feature, which leaves U.S. iPhone customers wanting.

The iPhone 3.0 software is available to developers today, and ships to customers next Wednesday.

Along with the updates iPhone software, Apple is releasing new iPhone hardware. The iPhone 3GS will sell for $199 in a 16GB version and $299 in a 32GB version. The existing iPhone 3G will continue to be available at a price of $99. (All prices with a 2-year AT&T contract.)

The iPhone 3GS will be faster than the iPhone 3G, and will include video capture, voice control, built-in support for Nike+ accessories, hardware encryption for Exchange users, and improved battery life. The phone will be available on June 19.