I disagree with this strongly, mostly because I hate conversations or meeting where people debate something which has a factual answer which someone with a laptop/internet/shell/calculator/IM client/Google can answer definitively in 10 seconds. Instead, people waste minutes (or, worse, say something will be tabled until later, perhaps calling an entirely different meeting!) to deal with it.

If you look at the most productive meetings at places like Google, people have data and processing capability to hand, and end up referring to it. If that is "IM the guy in another state who isn't needed for the meeting but has the a answer to this specific question", easy choice.