There is some existing research on racquet swingweight and the effect on the racquet. I recommend searching for a set of articles by "Rod Cross," a physics professor who is/was also a tennis amateur. Here is a link to some of his articles: http://www.physics.usyd.edu.au/~cross/publications.html
There is also a iPhone app that measures swing weight through a simple standard procedure using the built-in camera. It works based off the pendulum equation, but the use of the camera makes real-world measurement must more convenient. It only costs $0.99.