How many times have you gone into a conference room and found the whiteboards completely full of writing that you know is a month old -- any yet there's a big "Do Not Erase" on it?
My first thought was requiring people to append "...until 3/4/05", but that'll never happen.
My second thought was a small digitial timer affixed to the board, but enforcement is similarly a problem.
Finally, it hit me: fading whiteboard markers! They'd come in a variety of durations depending on your corporate policy: 1-day, 2-day, 1-week, etc.-- drzeus, Apr 20 2005 Actually, if markers in general faded on exposure to the air or light, this would also sold the problem of people writing on the board with non-whiteboard markers.-- nineteenthly, Apr 20 2005 I usually erase only the "Do Not Erase" and let someone else take the blame. These days, you could also easily take a cell phone picture of the board. But I still like the idea!-- Your_Name_Here, Sep 26 2009 //I usually erase only the "Do Not Erase"// Isn't it safer to erase everything except that?-- pocmloc, Sep 26 2009 writing "do not erase" on a white board is the mark of idiocy, nothing written under that quality of logic can be worth preserving.-- WcW, Sep 26 2009 random, halfbakery