For each area of the business we have two boards: planning and current. The planning board gets pretty messy, and is the place where we capture all the ideas that come to mind, comments and input are added to help prioritize those ideas as a must-get-to-next-week, or someday-this-would-be-nice. And the current board is the chunk of cards we are committing to getting done this week "no matter what". So, the current board stays pretty clean, and people work real hard to get everything cleared out of there each week, because then we can go to the planning board and grab some of the other high-priority things and check them off.

It isn't perfect, but it does keep us making forward progress. And sometimes those things that just don't ever make it to the current board are things that don't really need to get done.