>If Plan9 can 'plumb' a remote sound card, (a questionable example long >publicized) I'm sure it can do so with a mouse.
it isn't plumbing, but export/import, and it's useful. i had a usable sound system on my r3000 indigo, but my PC had none. on the pc, i imported the indigo's /dev and played sounds that way. i could imagine uses even a continent away (alarm system imports remote /dev and announces trouble). next door might be more useful.
