hey all. i recently hit w/ someone better than me (he could've actually made my college tennis team) and noticed that the main difference between me and him was the amount of swing speed he had on his shots, which translates to more power. my question is: how do i go about increasing my swing speed?? alot of people say that federer has tremendous swing speed and i would like to know i can also achieve. are there any particular weight lifting exercises i could do... ie side laterals, butterfly press, etc? or do i just have to hit as much as possible and develop them naturally?? FYI: i'm skinny (5'7" 120lbs) and i have the fischer pro 1 strung @ ~57lbs. before, my shots were mostly arm and they were loopy but now i'm using more hips and they've become more flat but faster. thanks for any input!!