Save your board -- keep it in a bag!
Dakine and Burton make some awesome board bags. If you are just going from the closet at home and into the car to drive to the mountain and want something to store your stuff in, then you don't need too much of a bag. Something with some moderate padding will do (like the DaKine Pipe or Freestyle).
If you are taking your board on an airplane, you want something more like the Dakine High Roller or Burton Wheelie. The pricier it is, the more padding and room you get.
NOTE: Here is a little tid bit for ya.
If you are putting your board up on a roof rack (exposed kind not the box carrier kind) you better darn well put a bag over it! (the cheaper ones have less padding and are perfect for this).
"But Frosty," you might ask, "I saw the pro snowboarders in on that movie and they had their boards up ...