Apple has released iTunes 7.3, which enables support for the iPhone. iTunes acts as the hub between the computer and the iPhone (much as it does with the iPod), handling synchronization of contacts, calendars, music, and movies. iTunes is also the interface for activating the iPhone's phone and data service plans; a video at Apple's site demonstrates the activation process. iTunes 7.3 is available via Software Update or as stand-alone downloads for Mac (a 33.8 MB download) and Windows (a 47.4 MB download). Note that iTunes 7.3 updates your iTunes library, so it's a good idea to have a current backup before you apply the update.
iTunes 7.3 also adds a requested feature to the Apple TV: photo streaming. Previously, photos could only be synchronized (copied to) the Apple TV.