I found this great looking chalkboard calendar by Pinch Design (a company in London). This is an idea that could work well with families with lots going on - teacher conferences, piano lessons, doctor appointments, soccer practices, and more. Everything is clearly written but can be changed at a moment's notice. Another good organizational idea: buy a box of colored chalk so everyone in the family could be represented by a different color on the calendar.
I think I could make my own: I know you can buy chalkboard paint, and I could use 2-foot square panels, and may-be just paint the name of each day on each one instead of above the panel like it shows in the picture. What a great project for my own “office” space!