If following President Obama on Twitter, Facebook and whatever else wasn't enough for you, the White House has published an iPhone app.
Available on Apple's iTunes store now (for free), the White House app streams up-to-date content from 1600 Pennsylvania Avenue directly to your iPhone or iPod Touch. Some of that content includes news, briefs, events, and live-streaming coverage of the President and other White House officials. (Apparently the State of the Union next week will be available for streaming from the Apple handheld too.)
The White House has certainly embraced using all sorts of technology to reach constituents. For the iPhone-less out there, the White House will be debuting mobile.WhiteHouse.gov in a few weeks.