Hard Drive
I guarantee that you'll only see image files get bigger
in the future. You certainly don't want to keep all of your
images on your hard drive, nor should you. However, you
definitely want to have a large enough hard drive to keep
everything you need fast access to. 120GB drives can be
had for under $100. If you're not squeamish about opening
your computer, you can usually install a second hard drive
in about 30-minutes. The other option is to buy a large
external USB 2 or FireWire drive, which don't cost that
much more than internal units. With Windows XP or Mac OSX,
these drives are almost always plug-and-play.