OS X: Getting used to Speech too much?

I found myself trying to instruct my Linux box via voice-commands this morning (before the first coffee). Am I getting too used to my Mac? Speech works like a charm. As long as my Sun does not start to do some serious work, that is. The frequency of the fans seem to cancel the reception of the microphone in my trusty PowerBook; same goes for loud traffic noises.
OTOH: If I'd start to talk to my Mac in the coffee-shop, who knows what people would think or do, anyway.