The drive connects to the Xbox 360 via USB and contains two integrated USB ports on the rear.

The six-pound drive, available from electronics retailers for $900, can also connect to Universal Plug and Play devices for sharing media throughout your house.

An external hard drive could connect via USB 2.0 or PCI-Express.

A hydroviscous drive consists of one or more discs or connected to the input shaft pressed against a similar disc or discs connected to the output shaft.

The drive connects to the camera via a special locking connector, though the camera and the drive communicate using the mass storage SATA standard protocol.

These drives typically connect to the computer's U.S.B. port, and can be found for about $40 in computer stores and at Web sites like PC Mall (www.pcmall.com).

The drive connects to the drive controller and other hard drives, if any, through a flat gray ribbon cable.

These drives connect to your system via an IDE cable and require you to open up your computer cabinet for installation in a drive bay.

The small key drive connects to the U.S.B. port on a Windows laptop or PC and immediately brings up a keypad for dialing phone numbers.

For example, few external drives connected via USB and Firewire correctly send S.M.A.R.T. data over those interfaces.