We could conceal the Chatterbox nodelet from unregistered monks, which would have the effect of concealing it from robots. This is done at
E2. However, since this community is not E2 and we want to entice newbies into our midst... making it obvious to them that there is a useful chat feature makes it imperative to leave the Chatterbox nodelet visible to unregistered visitors.
We might be able to play a guessing game with the UserAgent tag, and turn off the Chatterbox nodelet for any UA's that match a list of known spiders and robots. Since Google is our primary concern, that one should be easy to track down-- it's called GoogleBot I think and the UA string should be fairly evident in the Apache logs.