As performance improves and prices continue to go down, laptops increasingly replace desktop PCs at work.

A laptop offers a number of advantages, particularly portability. Even if your business doesn't call for much travel, you can take all of your data with you on a daily commute or just down the hall for a presentation.

Laptops recently made a big leap forward with Intel's introduction of its Centrino Duo platform. Intel's new dual-core mobile processors promise better battery life and improved performance, especially for busy multitasking professionals. AMD is also readying its dual-core mobile platform. 2006 promises to be a big year for laptops.

Most of today's notebooks, including both single- and dual-core machines, are just as capable as a basic business-desktop PC and require much less desk space. The best business laptops combine portability, performance, battery life and integrated wireless networking.

Why do I need a laptop?

What should I look for?

Should I buy a laptop or a desktop PC?
Before we discuss what to look for in a business laptop, you should figure out whether you need a laptop at all.

The latest Centrino notebooks with dual-core processors may be an overkill for business use, unless your job involves frequent video editing or gaming.

Desktop PCs typically cost hundreds of dollars less than laptops and if you're able to do all of your business comfortably from one location, you need not shell out extra cash for a portable form factor.

What advantages does a laptop offer?
A portable computer provides access to your files and applications wherever you are -- every corner of the world becomes an extension of your office. Riding the train or sitting in an airport, you can be just as productive as if you were sitting in your desk chair.

Your laptop can handle much more than just e-mail, spreadsheets, and word processing. Here are a few of the roles a laptop can fill:

• Presentation maker: Display your PowerPoint deck anywhere, anytime.
• DVD player: Whether you're waiting in the terminal or on the plane itself, watching a movie makes flying much more entertaining.
• Gaming machine: The most powerful business laptops are primed for gaming on the go.
• Jukebox: Invest in Internet radio, a CD drive and a big hard drive for MP3s. You'll never be without your music collection.

What are the disadvantages to using a laptop?
On top of the premium price tag, there are a few other drawbacks to buying a laptop rather than a desktop PC. For one, laptops are not as easy or inexpensive to upgrade as their desktop brethren. While it's relatively simple to add a bigger hard drive or a DVD burner to a desktop, on a laptop the operation can be more expensive, more complicated, or both. Here are a few other limitations to note:

• You'll be working on a smaller keyboard, looking at a smaller screen and probably sitting in a less-than-ergonomic position.
• You'll have to become conscious of battery life, an issue the desktop PC user doesn't have to worry about.
• You'll need a separate network hub and a backup solution. Laptops aren't optimised for those functions.

What can I expect to pay for a laptop?
There's a laptop for every class of business user. Currently, the least-expensive and least-sophisticated laptops start at AU$1,000 to AU$1,500. The smallest and lightest laptops can run to AU$3,000 and beyond. Very roughly, laptops cost about twice as much as their desktop counterparts. So all things considered, you should expect to pay between AU$1,500 and AU$2,500 for a nicely outfitted business laptop.

Are there hidden, recurring, or long-term costs of owning a laptop?
Because a laptop is likely to log many more miles than a desktop PC, it's inherently more vulnerable to wear and tear. You'll be susceptible to ailments such as worn-out hinges, broken keys, busted screens, and mangled optical drives. In the past, nearly all business laptops came with a standard three-year warranty on parts and labour. These days, some models include only a one-year warranty with the option to purchase an upgrade. Read your warranty information carefully before you make a purchase. Also, a decent laptop bag will help reduce laptop deterioration.

Why do I need a laptop?

What should I look for?

Why do I need a laptop?

What should I look for?

Processor Memory Video card Hard drive Optical drive

Screen size Weight Battery Networking Ports and connections

Processor
Intel's Pentium M, AMD's Turion 64 and Apple's PowerPC G4 processor offer business users the best balance between performance power, battery life and weight. For less demanding computing, an Intel Celeron or an AMD Sempron processor will do the trick.
Bare minimum: Regardless of what kind of processor you decide on, you'll need at least 1.73GHz of processing speed.

Memory:
You'll want enough memory to run a few applications at a time. The more memory you buy upfront, the longer your laptop will be able to handle current (and future) applications.
Bare minimum: 512MB.

Video card:
For most business users, video memory is one area where you can afford to cut corners. Unless your system will be doubling as a gaming machine, you don't need to shell out extra money for a high-end card with its own memory.
Bare minimum: An integrated graphics card that shares memory with the system chipset.

Hard drive:
E-mail archives, spreadsheets and Word documents add up. If you plan to carry music and video on your system, consider 80GB or more.
Bare minimum: 60GB; 5,400rpm.

Optical drive:
The least expensive laptops come with fixed drives that cannot be removed. A swappable drive bay offers more flexibility: You can easily pull out a CD-ROM drive and swap in a combo DVD/CD-RW drive (or even a second battery).
Bare minimum: If you're totally indifferent to the prospect of mobile movie watching, a CD-ROM drive will get the job done. But we strongly recommend upgrading to a DVD/CDRW combo drive, which will let you burn CDs and watch DVDs.

Screen size:
Depending on the type of work you do, you'll want to make sure your screen fits the job. Graphics and spreadsheet tasks call for larger screens while e-mail requires very little space.
Bare minimum: 12-inch display.

Weight:
A few kg here, a few kg there -- carry your laptop around the airport for an afternoon and it all adds up. You may be tempted to get a larger notebook that seemingly offers more bang for the buck, but trust us: For the business user, less is more.
Ideal range: 1.5kg to 3kg

Battery:
Laptop batteries don't last as long as they should. Even the best-performing systems top out at about 6 hours and most last half as long.
Bare minimum: One Lithium-ion primary battery with at least 2 hours of battery life.

Networking:
Today's business demands online connectivity. All laptops come with an Ethernet connection and almost all come with built-in wireless connectivity. You'll want both. If work takes you away from both office and hot spot, you can buy a laptop with an integrated 3G card, which connects to a mobile data network -- but that feature can be quite costly.
Bare minimum: Ethernet LAN connection and integrated wireless (preferably 802.11a/b/g) card.

Ports and connections:
The most sophisticated laptops feature advanced audio and video connections, such as digital media card readers, S-video outs for connecting to a TV, a DVI port for connecting to digital LCD monitors and a FireWire port for capturing and editing digital video. Unless you have multimedia aspirations, few of these are necessary for a business laptop.
Bare minimum: Two USB 2.0 ports; a VGA connector.

Editor's note: Part II, covering the best budget notebooks, will be published next month.