Everybody knows about BetaPlayer/TCPMP however incase anyone doesn't know yet it is possible to playback Ipod Videos (not ones from the actual ITunes store) on PPC/Palms.

Needed:

TCPMP Software for your OS:
http://tcpmp.corecodec.org/

ACC audio plugin for each device:
http://www.rarewares.org/files/aac/tcpmp_aac_plugin.palmos.0.66.zip

http://www.rarewares.org/files/aac/tcpmp_aac_plugin.windows_mobile.0.66.zip

I was suprised at how well the files played. I'm using an ancient Audiovox Thera w/ a 206 mhz ARM using the low setting (actually medim since they list the choices as Lowest, Low, Normal for some reason) so I imagine even the low end newer PPCs an handle the normal platform fine.

Source:
http://www.corecodec.com/index.php?option=com_smf&Itemid=29&topic=1843.msg12240;topicseen