This is really funny... and when I say funny, I mean it's very sad.
moon32# mv /usr/bin/mythfrontend /usr/bin/mythfrontend.real
moon32# cat > /usr/bin/mythfrontend
moon32# chmod +x /usr/bin/mythfrontend
Now... select TV from an orbiter, then repeatedly run "ps wax | grep myth". You'll see mythfrontend and mythfrontend.real. On the X display, Myth will start up. After a few seconds the mythfrontend process will disappear, but mythfrontend.real will still be there and you'll be able to watch TV (real slowly and with no sound on my MD, but what does that matter?).
BTW, this trick is great for parties. *Really* boring parties.