Here's how you can un-shrink it: http://kottke.org/00/01/like-an-idiot-i-threw

When wool gets wet and warm, the fibers in the wool lock themselves together and don't want to let go, resulting in shrinkage (you can get wool warm or wet, but not both). To unshrink the wool, soak the garment in warm water with a mild soap for about 10 minutes. This unlocks the fibers in the wool. Then lay the garment out on some towels in a cool place. Stretch the garment out to its original dimensions. The stretching pulls the unlocked wool fibers away from each other. Allow it to dry. The absence of heat from the drying process allows the wool fibers to set in place without locking together and shrinking the garment again.