Tomorrow Apple is set to unveil the first details of the next evolution in their iPhone OS.  Although invitations were sent out only days after Apple launched the iPad, speculation of upcoming iPhone features began not long after the iPhone 3GS was released last June.

Hardware teardowns of the iPhone 3GS by iSuppli revealed a dormant FM radio tuner that remains so nearly one year after the device hit the market.  It's possible we may see Apple finally take advantage of the inactive hardware.  Whether it's limited to FM receiving or if Apple opens it up to radio transmission remains to be seen but if utilized, it could adopt many of the same features currently in available to the iPod Nano.

appleevent4AppleInsider reported last month that their sources had confirmed the introduction of third-party multitasking would make it's way to the iPhone in the next major evolution of the iPhone software.  Described by their sources, Apple intends to utilize OS X's Expose feature to allow users to switch between background running applications. Within a similar report, a universal mailbox within Mail could make its debut in the 4.0 software update.

Reported earlier, MediaPost disclosed the possibility of Apple's acquisition of mobile advertising firm Quattro Wireless would eventually contribute to Apple upcoming iAd mobile advertising initiative.  Outbid by Google last year to acquire AdMob, Apple is set to compete with Google in the mobile advertising space, which we'll probably hear more about during tomorrow's event.

What do you think Apple will announce at tomorrow's event?  Be sure to check back tomorrow for all the details.