mplayer is indeed awesome. I use it on all of my Linux boxes. I've got some bash scripts working now that can stream my lossless audio files from my home computer in a much smaller mp3 format to my n800 or other machines. It's useful for streaming audio over the internet. The client side plays the audio with mplayer. I'm working on making it stream video in an internet and n800 friendly way also. Hopefully it will someday autodetect what kind of audio/video is being played and convert it for streaming. Right now it uses various audio decoders + lame mp3 encoder + netcat.