If you have small children, chances are you have writing on your walls, or have had to clean it off at some point.  Something about the wide-open, blank canvas of a pristine white wall is simply irresistible to many kids.  If you want to encourage their creativity while keeping your house clean and your sanity intact, you can turn your wall into an easel that, when they're done playing with, requires no scrubbing or cleaning.

I Can't Let My Kids Draw on the Wall!
In my opinion, it is almost impossible to prevent kids from drawing on the wall once they discover how fun it is.  My 18-month old daughter just discovered her inner artist, and no matter how careful we are about keeping pens, pencils and crayons picked up, she manages to find one and pull a Picasso before we have a chance to notice.  I think this is a case where you can go with the tide or be washed under.Cultivate Their Inner Artist
With just a couple dollars, you can create a removable canvas on the wall for your kids to act out their artistic passions.  All you need is some poster board, currently around $.20 per sheet at our local Walmart and some staples or tape.  I like to get enough poster board to cover their entire reach so I don't have to worry about them accidentally going off the paper.

Join the pieces of poster board together, staple or tape them to the wall, and let your kids go nuts.  Both of mine love the thrill of the forbidden and get hours of fun drawing on the "walls".  Once they are done or have filled the poster board up, we can simply remove it and move on.