Buying a new notebook or laptop computer can be tricky business. However, I suspect that much of the complexity is created by manufacturers who have made us focus on technology so much that we lose focus on what we're going to actually use the computer for. I suggest that when buying a laptop the focus ought to be less on specs for their own sake and more on functionality.

Main system / desktop replacement

There's a real market for desktop replacement systems. These tend to be larger units with screens of about 15" or more. If you're planning to use a laptop as your main or only computer then this is the class you're looking at. You'll need to set your budget at a level that'll allow you to buy plenty of RAM (2GB as a minimum and 4GB if you can afford it), a decent hard drive (120GB as a minimum) and the fastest processor you can manage.

Accessory System

This is the really confusing market - made all the more confusing since the stunning arrival of the Eee PC. An accessory system is one that's used to complement a desktop system. For example, I do most of my "heavy" work (like Photoshop and video editing) on an iMac. My MacBook Air is used when I'm out of the office and need to work on a document, retrieve email or browse the web.

Buying a laptop to complement your desktop is a study in managing compromises. You'll want a system that's small and light enough to carry but has a decent screen and keyboard. The amount of storage you'll need probably won't be far in excess of 80GB as all you'll be carrying around is the data you need while you're out and about. Likewise, you probably won't need mountains of RAM as you won't be using it for lots of complex work.

So, once you've decided whether you're in the market for a main or accessory system it's time to think about budget. That's easy - work out how much money you have and don't overspend. Once you've settled on screen size, RAM and disk, simply get the fastest CPU you can afford.

Good luck.