Many of us remember when a 20 MB external hard drive, hooked up to a Mac Plus, was a luxury. These days, you donít want that little amount of memory in a Compact Flash card in your digital camera, let alone attached to a computer. The iMac comes with a 250 to 500 GB internal hard drive. For many that may be adequate storage at first, but if you save a lot of music, photo or movie files, it is not
