Guess Partition magic is familiar to most folks around.
However, I wanted an Free Open Source solution addressing the same purpose.
My searches have led me to parted
and it's gui-enabled frontend gparted
There's a gparted live cd,
which is a bootable linux cd which takes you straight to the gparted gui.
Also, gparted is available on the "SystemRescueCd" liveCD distribution.
Also, here's a good link on using gparted to partition hard drives on Windows Vista preinstalled laptops.