GParted Partition Editor.
GParted is a "free" open source hard drive partition editor to handle your disk partitions via a graphical user interface. GParted is distributed under GNU General Public License version 2 or (possibly) later version.
Personal comment: The best partitioning program I've tried so far.
Lastest stable version: 1.5.0
Super easy, with GParted, you can resize, copy and move partitions without loss of data.