Found this interesting post describing a successful approach to rapidly designing multiple concepts within a short time period, at Autodesk:
http://dux.typepad.com/dux/2009/06/speed-racer-collaborative-sketching-saves-the-day.html
I’ve encountered this scenario a few times in my career thus far, most recently at Netflix (we actually just had ONE week!) and last year at Cisco (also just a couple weeks) with an outside vendor flown in from Taiwan. While each effort was for different purposes (sales pitch vs. concept exploration vs. new business ideas, etc.) inevitably the experience was a kind of “trial by fire” bonding moment for the team. Such projects really showed off our “true colors” so to speak as inventive, committed, multiply talented designers trying to work together intensively. Also surfaced in a very real and powerful way the notion of “shared responsibility” for the project and relaying that with non-design peers (coders, managers, etc.).