Was on a call with a group of directors reviewing a presentation for some set of functionality to be delivered and the discussion was heated and lively. At one point I IM'ed the technical lead and asked what she thought - she'd been pretty quiet. She sent back: with so many geniuses on the phone, I don't think I'd have anything of value to add ;-)
You know, the temptation is very high to jump in and share your mind. but sometimes it's just better to be quiet.