AdMob, the mobile advertising network recently acquired by Google, has launched a new “Interactive Video Ad Unit” for the iPhone. The new ad unit promises “true interactivity,” offering in-player actions that enable users to browse Web sites, view additional videos, and more while the video is playing. AdMob says the unit will be sold primarily as an interstitial that will automatically play as an application loads, but may also be accessed through banner ads. In addition, AdMob creates multiple bitrate encodings of the video files for each and then dynamically streams the most appropriate file size based on the devices’ EDGE, 3G, or Wi-Fi connection, utilizing its network of globally distributed servers to ensure the fastest possible video load times. According to the company, AdMob’s iPhone ad network reached more than 20 million unique iPhones and iPod touch devices worldwide in 2009.