That's why this bit of blog has been so long in coming. Much like any good speech, toast or presentation, a blog should have something to say and should say it well. Concise, well-organized and thoughtful is preferred to wordy, rambling and haphazard.
In that vein, the thought occurs "What if I have nothing to say but I must say something?". For those times when you are in situation where you need to exhibit some leadership, thoughtfulness or insight - but find yourself (momentarily) bereft of any of these - don't simply open your mouth and start yammering. Instead, rise above the fray and simply Ask a question.
Grasp onto whatever threads of conversation you have heard and think of the basics: What? Where? Why? When? How? Who?
There are always questions, you just need to keep a questioning frame of mind. So often we are called on to know that it seems we can't ask questions and show that we don't know. But remember, the quest to know more always begins with a question.
Sometimes it's hard to ask the real questions you have, to the people you are with. Such as your boss. I can understand the dynamic where quizzing the boss isn't going to get you very far. So, try asking yourself the question. Very often the phrase "I was asking myself..." is the perfect way to open a line of questions to a group without threatening, challenging or badgering anyone.
Try a mental exercise (or as a game with friends): As you listen to or participate in a conversation, pretend the only thing you can do is ask questions. No statements, assertions, or exclamations that aren't in the form of a question. It's actually pretty fun.