if you use Ronaldinho in arena mode there is a cheat in fifa09 ( a mark on every pitch inside the centre circle) and if you put the ball on this mark (dribbling to it) and then left/right on the dpad to change to freekick mode you can hit the crossbar from inside the centre circle everytime... Ronaldinho can hit the crossbar twice with one shot!!
put the ball on the mark
change to free kick mode
hold X/square button to power up to just past the last inner mark on the power bar...
while holding down on left stick for after touch
im sure everyone knows this thats why no one is posting videos.
ps. you need a hi res screen to see the mark clearly (my mates tv is blurry and its really difficult to stop the ball on the mark)