We did some chalkboard paint in one of the kid's bedrooms, then on a lower kitchen cabinet. Now we added two more cabinets in the kitchen. Our concern was the chalk dust on the counters, and I am pleased to say it hasn't been an issue.
AND-- we can practice some pesky sight words and lowercase letters that look similar.
My older son also asked why we spent so much time in preschool learning uppercase letters, and now, in K, everything is in lowercase! That's a good point.