Last year Mozilla funded development of Leonora, David Schleef's port of the Theora decoder to run on the TI C64x+ DSP that's found in the Nokia N900, Palm Pre, Motorola Droid and other mobile devices. Since then Matthew Gregan's spent some time working on integrating it into a complete player with actual video playback, sound, and A/V synchronization. The bottom line is that using Leonora and certain graphics acceleration tricks we can play full-screen video (800x480) with sound at 26 frames per second with the CPU 80% idle. This shows that free codecs can work well on mobile devices. Read Matthew's blog post for the juicy details.