At August 2009 OLPCLearningClub.org, Kim presented XO Music in the Cloud computing environment with several issues, imo: (Note: Prezi.com site was kewl with zooming capability for visually impaired, but said not to run on the XO Mozilla browser, iirc.)
- Restricted, Adobe Flash dependency,
- open source gnash browser plugin has issues with certain websites,
- online dependency of web browsing
- mp3 format Restricted Formats even for an open source jamemco? music library site?
- caching and bandwidth issues (browser up on a XO-1 + media playing)
So as an alternative, to install MP3 movie and audio playing capability, some streamtuning  package (captured a LUG Linux on Kojo NPR talk, a very long time ago from a desktop machine with high speed wired connection), and other text browsing that might eventually become a text format alternative to the presentation
Either with a browser download the freshrpms package 
Note: close the browser as yum is memory intensive and may %pre %post error causing conflicts that require a clean reinstall start the Terminal Activity su root # or become root icon top right wget http://ftp.freshrpms.net/pub/freshrpms/fedora/linux/9/freshrpms-release/freshrpms-release-1.1-1.fc.noarch.rpm rpm -ihv freshrpms-release-1.1-1.fc.noarch.rpm yum install mplayer streamtuner mpg321 lynx yumex
- yum may load package definitions, if you've never used yum on that machine, or getting current data
- answer some questions, Yes install, if enough space and OK with restricted formats, etc
- import gpg keys for repos, if OK with you to go off the yellow brick road, so to speak...
Note: The Yum (Yellow dog Linux Update Manager - written in Python for Apple Mac Linux distro at Duke, iirc) handles dependencies, but some Fedora Core 9 repos are currently timing out over the 6 month release cycle?) so gave many HTTP 404 Not Found errors, and Fedora 11 presto deltarpms will reduce bandwidth and other goodies, but will need a back ported F11 for XO-1 release...
- Yumex is the windowed but not sugarized? yum gui, and may hang the machine, requiring hard power button off and on to reboot...
- Lynx is a text based browser occasionally useful for quick connection low overhead/bandwidth stuff
- Others present liked RealPlayer for streaming media from NPR,
but that is non free as well,
- HelixPlayer is the community version, but
still run into codecs (code decode file format reading/ writing) of audio and/or video files on content offered from websites
- and that's without DRM (Digital Rights Management, a copy protection scheme), etc
So, will see if I can do that full alternative solution...
Seems like a simple protocol like
- HTTP, NFS/ Samba or FTP protocol
- local or remote file service caching files
- to your thin client like XO,
- somehow select which files to play, maybe
- randomplay (a perl script that randomly jumps around a directory of files) might do the trick, or at least amongst your personal collection
- Grip will encode on a desktop with a CDRom/CDR/DVD drive).
- Ogg is a good free format, MP3 has royalty/ restricted format issues.
- Ogg Convert with a GUI interface on Fedora your collection to convert .mp3 to .ogg encoded formats.
And grab new interesting audio files from the web as able, save to USB or on a desktop machine, then transfer to XO or file server, or leave on USB/SD storage...
Also, I find a cheap MP3 player with USB connection,
- (or GeeXboX a Sandisk Sansa, iPod or even a 1 Gig Colby as USB storage)
- occasionally add external speakers like
 OLPC Learning Club RAFFLE WINNER! :-) for presentations, though recycled plastic instead of paper may be longer living for packing & repacking the speakers, and stronger packing material might help the rugged ways I end up carrying gear on a bike and other ways...
Or Headphones! Especially good for kids insisting on playing with Speak Activity before they know how to read/ write/ type/ not deliberately annoy grouchy old adults such as UncleCrazy...