QUOTE(cartographer @ Feb 16 2009, 09:55 AM)
Anybody knows what is the meaning of 'swingweight' of a racquet and how does it affects our game?
QUOTE
Swingweight is a measurement of a racquet's resistance to being rotated about an axis going through your hand. A low swingweight makes it easy for the player to swing the racquet (maneuverable). But it also makes it easy for the ball to move the racquet, resulting in loss of power.
Swingweight is determined by both the amount of mass and its distribution in the racquet — distribution being much more important. The farther an amount of mass is located from the hand, the more effect it will have on stabilizing the racquet.
...got that off the 'net

...good thing i checked, since i was going to answer something about hanging a piece of weight from the tip of the racquet and the effect from swinging that around

...fortunately i remembered that was for measuring the stiffness of a racquet...
...anyway, basically it means how the racquet feels when you swing the racquet, in that it feels head-heavy or head-light... the former makes the racquet more stable on impact but at the expense of mobility while the latter makes the racquet more manoeuvrable but less stable i.e. twisty on impact... depends on the user really which one they prefer...
...i still remember when i first bought and used the wilson hammer profile way, way back then... (they'd just released the range...) *nostalgic* wow, that was kinda revolution in racket technology, i suppose... where the racquet felt well-balanced when you swing it, but the weight was actually all in the head, making it very stable on impact but quite easy to swing... too bad it was just too stiff (brittle actually) for my game... i cracked both my racquets so i sold them to my juniors

...anyway, swingweight generally determines whether a racquet suits a baseliner or serve-and-volleyer... please correct me if i am wrong, though... agassi* wannabes will choose a more head-heavy racquet while sampras* wannabes one with more mobility i.e. head-light... that's some (incorrect) generalisation, but you get the idea...
* i guess these examples give away that i am from that generation