A PC Card, also known as a PCMCIA Card, offers an easy way to expand your laptop; just pop the card into the PC Card slot (almost all laptops have them), and you have Bluetooth, Wi-Fi, a cellular modem, a memory-card reader--even a TV tuner.

PC Cards come in three types: Type I cards (3.3mm thick) are mainly used to add memory, Type II cards (5mm thick) are generally used for network adapters, and Type III cards (10.5mm thick) are often used for hard drives.

Sherlon, to answer your second question, ExpressCard is the next generation of the PC Card. The numbers indicate the card's width: ExpressCard/34 devices are 34mm wide; ExpressCard/54 cards are 54mm wide. Aside from being smaller than existing PC Cards, ExpressCards promise data-transfer rates that are twice as fast. That faster speed means the cards can be used for high-bandwidth interfaces, such as Gigabit Ethernet ports and HDTV tuners.

The standard is still relatively new, and so far, ExpressCards are on store shelves only in Japan. But as expansion-card manufacturers switch over to the new standard, this type of PC Card will become more common in the States and other parts of the world.

Find out more at the ExpressCard site and in our News.com story about the technology.