PC Cards vs. ExpressCard
The PC Card, a credit card-shaped device that plugs into a slot on your notebook, can provide a number of connection types--modems, USB connections (say, for your digital camcorder), and wireless WAN radios are all available in PC Card form. PC Cards are handy because they're easy to upgrade and because you can buy third-party PC Card solutions after you purchase your notebooks. However, most notebooks come with only one or two Type II PC Card slots, forcing you to limit the number of PC Cards you can add.