Lunges combined with various upper body patterns are some of the most versatile and effective exercises for an athlete. They activate and strengthen the myofascial chains of the body.
Here are a few examples of lunges that improve some of the most important movement patterns needed for function and performance.
More about lunging:
General theory: http://en.wikipedia.org/wiki/Lunge_(exercise)
Variations and videos: http://www.coreperformance.com/search/?keywords=lunge