If you are going to the inauguration, you can take pictures (under 10MB in size) of the event and send them to email@example.com.
CNN will then use Microsoft’s PhotoSynth software to create a massive 3D image. It will be interesting to see how well it works, especially since most of the event will be covered with people. Since the people move, it’s not clear how well the software will be able to match images up. But PhotoSynth has created great 3D experiences in other locations.
UPDATE: See the results of CNN’s PhotoSynth project at CNN’s The Moment site.