Here is an exericise that is said (by bodybuilding.com) to be "The Absolute Best Way to Improve Your Leg Strength and Power for All Sports". If mastered you will definetly increase you vert, balance, speed, and coordination.
http://www.bodybuilding.com/fun/legpower.htm
It is a bitch to learn, but it will definetly help you out in the long run. I'm start doing them some more because i had to stop but i could only do 1 but i am looking to be able to do 5 each leg
Edit: You're only suppossed to do 3-5 reps atleast five times per day, and do more reps for your weaker leg. So add around 2 sets of 4 reps per leg rest a minute then do 3 sets of 4 reps per leg. to your workout or whenever you want to do them (I'm going to do them Every workout.)