We did this when we renovated. Had a kitchen wall section chalk board painted for notes, as well as a much larger section of the kids play room wall.

The notes was useful space on the kitchen and the playroom one the kids just loved to doodle. Their friends were always impressed and loved to be able to leave a tag or doodle on it when they came over.

We tried a layer of magnetic paint too, but it didn’t work nearly as well.