If you're using the packaged version, you need to use the discover script first to obtain the MAC address of your 'mote, then edit the control script with it. It's all in the documentation.
Yeah, I'll definitely look into the nunchuck this week. Classic I don't own, so cannot help in that regard. PS3 controller should be as easy to map as the wiimote (+nunchuck), but I don't have one of those either. Maybe someone who does, could add the support based on these scripts.
Anyway, when you look at the vga output project, combine it with this (maybe two controller support), you have a really nice gaming setup.
PS3 controller would be sweet, but the pairing isn't as easy as in wiimote. PS3 controller needs to paired using USB. And afaik, n900 doesn't have usb-host which would make pairing PS3 controller impossible (??). There might be some way of getting around it, though.