I used both Partition Magic an Drive Image millions of times (PowerQuest releases, not the Sickmantec ones). It's pretty much self-explanatory.
You can copy a partition to another drive with Partition Magic. With Drive Image you can make an image of a partition, save it somewhere, and extract it to another hard disk/partition.
TheMajorMMX - Intel P200 MMX @ 225Mhz - V-Tech (PcPartner) Baby-AT mb w/ Intel Triton TX chipset - Nvidia Riva TNT2 M64 w/ 16MB - 256MB M-Tec SDRAM - Still running.....