Kicking without keyboard is a must for majority of the kicking excercises. Advantages include: working on stabilizing body (your core), improving balance, easier on the shoulders and much more. If you have to use a kickboard, cut it in half, so it is small and makes you work.
More instructions over at his site. I prefer running over swimming, although swimming is probably better for you in the long run. At least that is what my friends tell me.