H.264, like MP3 for Video
The New York Times: Packet8 phones also do not use the new H.264 video encoding and decoding scheme, which provides high-quality, 30-frames-a-second images with half the bandwidth requirements. In some ways, the new codec may mean to video what the MP3 compression format has meant to audio.
Apple also has some interesting stuff to say about H.264
http://www.apple.com/macosx/tiger/h264.html