Chalkboard contact paper - cut into labels, stick on cans or glass jars, re-use for different things, just write on the label! Also stick on front of Ikea sliding drawers to label (easier than painting chalkboard on that surface) Chalkboard sheets too: http://www.amazon.com/Wallies-Stick-Chalkboard-Sheet-Slate/dp/B0016KQZGQ
You've picked your color, but how many gallons will you need for your room? Calculate the wall area of the room; you'll need one gallon for 450 square feet. To determine the wall area, multiply the height of each wall by its width (don't subtract for doors and windows unless they take up more than half the wall); total the figures for the walls. Add 10 percent for future touch-ups. For two coats, double the number.
DIY Chalkboard Paint. I don't know if this personally works or not, but if you have a little left over grout and a little left over paint, might be a fun project to try on a piece of the wall in the garage by the light switch.