The PalmOs does not restrict what media you can view - the media player options do that. While there are several pay-to-run media players, there are a few open-source media players too. I use TCPMP. Once I installed all the codecs I was able to watch most video formats and listen to most music formats. I use TCPMP as much or more than RealPlayer since ti will open formats besides MP3 and RM.
I have run across only 2-3 files whose format was not compatible with the TCPMP software. Since it has been a while since I installed TCPMP, those formats maybe accessible too now.
I rip my DVDs with VideoDVD-Rip in Linux and then move the 320x320 movie to the SD card via my card reader (bluetooth is WAY too slow for this job). I can watch 2 hr movies with ease. I rip to 320x320, 192 kps, Xvid4/AVI with 64kps stereo sound (if the source is stereo). I set my target size to 230MB for a 2 hour movie and about 85MB for 1 hr color TV shows (I own several TV series DVD collections).
It's a nice way to pay a few minutes during lunch, while in a waiting room or in bed before sleep. The 320x320 screen at arm's length is about the same size as our full size TV as viewed from across the room.
I'll be anxiously watching the Linux PDAs. We switched to Mandriva Linux in mid-2005 and won't be going back to Windows anytime soon due to their business practices/near-monopoly status/etc and b/c with Linux I can do what I want to do - not what the various marketing departments of the software companies want me to do. The constant commericalism found in Windows, on some websites, and in the media players makes us crazy. I switched to "Real Alternative" aka "Media Player Classic" at work so I can view my files or listen to my music without the Windows Media Player commercialism.
Love the O'Reilly website and articles.