Besides the extras talked about so far, you can supplement or replace some of the essential components of your computer system. Here are several options that you can connect using your computer's USB or FireWire ports:
CD Burner ” If you don't have an Mac with a built-in CD burner, you can buy a standalone product with much of the functionality. Separates, however, might not be able to take advantage of Apple's ultra -slick, Finder-level CD writing feature.
Hard Drives ” You can add extra hard drives to your computer for additional storage, which comes in handy especially if you plan to work with space-hogging digital media. The only consideration is that the USB port doesn't really exercise the maximum speed of a large hard drive, so you might prefer FireWire, if your computer has that feature. USB drives are fine, though, for occasional use or just to back up your precious files. You'll learn more about backup possibilities in Chapter 28, "Managing Your System."
Input Devices ” You're not limited to your iMac's keyboard and mouse, although they are suitable for most folks. But it's nice to know there are alternatives. If you've migrated from the Windows platform, for example, you'll be able to take advantage of a mouse with extra buttons (the second being used for the context menus you otherwise invoke when you Option-Click on something). In addition, you can purchase joysticks for computer games , keyboards for special needs (or just in the form of those offered on regular Macs), and even trackballs ( sort of an upside-down mouse), which some prefer to a regular mouse.