When joining a new pair (and you're going to play the role of navigator with Beginner's Mind), don't allow your partner to explain anything to you. Join the pair with the simple question--"what card are you working on?" and then read the card yourself. The rest of what your partner is about to say is probably information you already know, or don't need to know yet, or just plain boring. Make sure that you are driving--maybe watch silently for 1 or 2 minutes, and if you still don't know what's going on, ask a question. In this way, you begin to truly collaborate with your second question, instead of trying to "get up to speed". If you're playing ping pong and don't know where you're going, keep asking questions until you know enough to drive.
I learned this trick from a colleague of mine back in New York (sorry, I'm not sure if I can get away with revealing my former employers' names), but still I want to give credit where it's due--thanks, John Mullaney!