Using a huge frame w/ a desktop size Calendar. If you can, get the style that will allow you to easily slip each month into the side. White on the glass with small tip dry erase pens. You can even color code per person and group events.
I am totally in love with this idea from Tatertots & Jello: 26 of my Favorite DIY Projects from Not only is the use of peg board in these fancy-shaped frames clever, but take a closer look at all of the ingenious things she used as organizers.