I've successfully gotten lineakd to compile and work on my C3K and I'd like it to work for the other clamshells as well. lineakd is basically a daemon which runs in X and listens for special keypresses. When a key is pressed it will run any command you want. I've gotten it to work very well on my C3K with my CE-RH2 audio remote controlling mpd via mpc. mpd is the music player daemon and mpc is a controller for it. (I've also added other mpd clients to OE but that's beside the point.)
I'm looking for a C7/8x0 owner with a CE-RH1 audio remote to get me the X keycodes for their remote. To do this easily you need another linux machine with X installed (remember that you can always use Knoppix on, say, a Windows computer to do this). Bring up your Zaurus and get into GPE. Run "xhost" on the command line with the IP of the other Linux computer with X (ex: xhost 192.168.0.45). Go to the other linux computer and open a terminal. Set DISPLAY to go to your zaurus (ex: export DISPLAY=192.168.0.42:0.0). Now start "xev". You should see a window pop up on your zaurus. Now press each of the keys on the remote and look for the "keycode XXX" entry in the output. Note the keycode and which key it is. Post the info back here or PM it to me and I'll add support for the CE-RH1 to lineakd. I'll even help you set it up if you like.