There are several other systems on the horizon of which you should be aware. They are based on a phase-change technology. Without going into details, a laser beam heats spots on the disk causing them to change between two states, shiny and non-shiny, corresponding to ones and zeros. This technology uses a laser to change the optical polarity of the disk surface, so that it creates spots that appear either light or dark. You put your own IDE drive into it.
People often install a smaller hard disk that has been made redundant by a newer one.
The unit plugs into the parallel port of your computer, and is another good method for backing up, or moving data between machines. It is a favorite for those skittish about opening their machine. The bottom line is to decide what is best for you assuming that you are reluctant to be on the bleeding edge of technology. I consider the ZIP drive an excellent value for the home user. It is useful also if you have more than one computer and do not yet use a home network.