Many people use a notebook as their main computer. And if you're like me, you need to connect all sorts of stuff to your notebook: printer, scanner, Zip drive, George Foreman grill, you name it.

Most of the time, those devices (except the grill) connect to one of your notebook's Universal Serial Bus ports or, in some cases, a FireWire high-speed port, also known as IEEE 1394 or I.Link. The beauty of both types of port is their plug-and-play simplicity and the ability to use most USB and FireWire devices on either Windows or Mac computers.

But as with all things technology related, that scenario is getting a bit more complicated with the emergence of new standards. Aside from that, some devices (such as hard drives) now come in both USB and FireWire versions. So how do you know which one is right for you?

Let's start with the main question: What are the differences between FireWire and USB? Then I'll talk about why you should care.

Before FireWire and USB appeared, external devices were typically connected to a computer using serial and parallel ports. But those connections had many limitations: data transfer rates were sluggish, devices couldn't be unplugged without causing your computer to crash, you couldn't easily swap multiple devices on the same port, and so on.

In the mid nineties, the connectivity situation began to improve dramatically with the introduction of FireWire and, a few years later, USB. Both technologies offer faster data transfer rates, true plug-and-play connectivity, the ability to unplug one device and plug another into the same port without rebooting, and more.

A serial input/output technology invented by Apple Computer, FireWire can transfer data up to 400 megabits per second. FireWire connections are offered today in many notebooks, digital camcorders, and digital cameras, and some external hard drives, CD writers, and other devices. (Next week's newsletter will look at FireWire and USB portable hard drives.)

A FireWire upgrade is in the works. IEEE 1394b will offer transfer rates of up to 800 mbps, reportedly fast enough to copy an entire CD in seconds. Currently, no notebook or desktop computers comply with this new standard; the first models will most likely desktops and are expected at year's end.

This competing serial input/output technology was introduced in 1997. USB ports are found on most desktop PCs, notebooks, and peripherals today. There are far more USB devices than there are FireWire peripherals, and they usually cost $20 to $40 less. But the current USB standard, version 1.1, is considerably slower than FireWire, with data transfer rates theoretically up to 12 mbps (real-world transfers vary by device type and are much slower).

The new USB 2.0 specification promises data transfer rates of 480 mbps, which is 80 mbps faster than FireWire. At this time, however, notebooks (and desktops, for that matter) with USB 2.0 ports are scarce. That should change within the next six months. Gateway, for instance, has vowed to put USB 2.0 ports in all its computers by year's end. Meanwhile, several new peripherals, such as some portable hard drives, use the new standard.

It's important to note that USB 2.0 devices are backwards-compatible with USB 1.1 ports. While you won't get the increased speeds, you can use a USB 2.0 device with your current notebook's USB 1.1 port.

One advantage that FireWire devices have over USB devices is the ability to draw power from the computer. Standard FireWire cables have six-prong connectors on either end and consist of six wires, two of which can carry power to external devices. That means an external FireWire hard drive could run without AC power when connected to a notebook's six-pin FireWire port. In theory, that's a big benefit for travelers. You'd be able to back up your notebook's hard drive to an external drive while on a plane, for instance.

But it's not that simple, unfortunately. To save space and conserve power, many notebooks come with four-pin FireWire ports. External devices must connect to them with a four-pin cable or six-to-four-pin adapter, which means you lose the two power wires of the six-wire FireWire cables. These devices must use an AC adapter in order to operate on a notebook with a four-pin FireWire port, meaning that notebook owners with four-pin FireWire ports have to forget about backing up to an external hard drive while flying over the Rockies.

Many FireWire devices ship with the standard six-pin cables, so those with four-pin FireWire ports will need a four-to-six-pin adapter (about $5 to $15) or a FireWire cable with a six-pin connector on one end and a four-pin connector on the other (about $20). Check out StarTech.com for FireWire accessories.

On average, FireWire devices are more expensive than their USB counterparts--but usually not by much. For example, Iomega's 80GB external FireWire hard drive was selling recently at PC Connection for $300, compared to $280 for Iomega's 80GB external USB 2.0 drive.

The bottom line? If you're in the market for a new notebook, consider one with USB ports as well as a six-pin FireWire port for the greatest speed and flexibility when traveling. That's easier said than done, however, as many computer makers don't differentiate in their product literature between four- and six-pin ports. If the FireWire specs are unclear or unstated, call the manufacturer for details.

If the peripheral you need is USB-only, hold out for a USB 2.0-compatible device, if possible. Even if your current notebook has a USB 1.1 port, you might be upgrading at some point to a computer with a USB 2.0 port, so the faster peripheral may be a better investment in the long run.

Of course, you could also consider waiting until notebooks with USB 2.0 ports are available. Some vendors may even offer models with both USB 2.0 and FireWire ports, though which manufacturers and when isn't clear at the moment. Keep in mind that new technologies usually appear in desktop computers first, so it could be six months or so before there's much of a selection for notebooks with USB 2.0 ports.