Taiwanese computer parts maker Asus obviously didn't get the memo.

Didn't Asus know notebook computers need hard drives? Or that they're supposed to run Windows — and that the pre-loaded software must bloat the boot-up process to the length of a long weekend?

Don't they know you don't just go selling laptops for less than $750 — let alone $400 — unless the hardware has been aged like whisky?

Asustek Computers Inc. went ahead and broke the rules with the Eee PC. And we should all be thankful.

• Click here for FOXNews.com's Personal Technology Center.

A scrappy, aggressively priced two-pound notebook with a surprisingly broad set of features, the Eee PC is a no-brainer purchase for tech-savvy travelers who want to downsize their luggage at low cost.

It also makes a great gift, at least as practical as Apple Inc.'s iPhone and about the same price.

In the month I've owned an Eee PC, I've used it to watch movies on an airplane, read my favorite blogs and news articles — archived automatically — and update my online calendar while on the road.

Its quick boot-up has made it perfect for writing quick e-mails (and this review) whenever I had a moment of inspiration.

I'm not tossing my larger notebook computer, which I'll continue to use for editing photos and for other tasks that feel constrained on the Eee PC's tiny, 5-inch screen.

But it's hard not to be impressed with a full-service laptop light enough to be carried along with sunscreen and a magazine in a flimsy plastic bag, as I did during a recent trip to Cancun.

As it refines the software and instructions, Asus — better known as the world's largest maker of computer motherboards — could garner a following among mainstream computer users who right now might be puzzled by some of the eccentricities of Linux.

The $400, seven-inch Eee PC is a new entrant in a fast-growing market for ultra-portable PCs.

All such computers, including the Eee PC, require sacrifices. Its keys may seem painfully small. For people used to a desktop or a standard notebook, its screen makes you feel like you've just moved from a McMansion into a studio apartment.

(Tricks for maximizing screen real estate when Web surfing can be found on the helpful user forum, Eeeuser.com.)

Unencumbered by Windows, the Eee PC boots up so quickly I didn't bother counting the seconds.

Its Wi-Fi chip links with the Web in a flash, and its Webcam — a feature missing from many laptops triple the price — turns it into a video messaging device with the help of eBay Inc.'s Skype, which comes pre-loaded.

There are USB ports for peripherals, a port to connect to a monitor, and — most essentially — a flash-memory slot to expand its meager storage. Battery life is advertised at 3.5 hours.

The Eee PC's custom version of the Linux operating system has a simple user interface that takes some getting used to.

It organizes the software by tabs — Internet, Work, Learn and Play — but many users on the Eee PC forum dislike its look.

An upgrade to a more familiar, Windows-like interface is available in "advanced" mode, which can be activated with a few minutes of careful programming.

(But you'll do that at your peril. On my second day, a badly written command crashed my system. I had to reinstall the original software.)

The Firefox Web browser, Adobe Acrobat Reader and OpenOffice — the open-source equivalent to Microsoft Corp.'s Office — come pre-installed, as do a music player, a video recorder and some addictive games.

Google Docs — an online document suite for storing files remotely and sharing them — is also configured.

Links to Yahoo Mail, Gmail and other e-mail programs are already on the desktop. A messaging program called Pidgin worked with AOL Instant Messenger and Google Talk.

Skype, the voice- and video-calling program, also worked well when I called home from the international airport in Hong Kong.

Users willing to learn a few Linux commands can add the Picasa photo sharing program, Google Earth and Audacity, a free audio editing program beloved by bloggers.

The Eee PC runs quickly, despite a low-power processor. A disk drive made of memory chips is fully functional, but the four gigabytes installed on my model was insufficient for my needs. A memory card I purchased separately for around $30 doubled the space.

The Eee PC's software package leverages recent advancements in open source and online software. It may be hard to believe, but you won't miss Microsoft Word, or Windows, for long.

While much of the computing world was focused on Windows Vista (or spending hours trying to navigate its upgrade process), big software companies were releasing new and upgraded versions of familiar software packages for Linux.

The Eee PC can be retrained to run Windows. But it can feel like a major commitment.

Asus's exhaustive instructions include a 12-step installation, a four-step "optimizing" process and another 25 steps to get the operating system to play nicely with the Eee PC.

(I'm thinking of giving my friends copies of one of the instructions, "Deleting unnecessary Windows components.")

The Eee PC is not easy to find. At a large Manhattan computer store in November, a clerk told me the store was out of stock.

And why wouldn't he? If a $400 PC sat next to higher-priced competitors on the shelf, would so many people spend $2,000?

I made him check the store's inventory in front of me, and there were more than 40 Eee PCs in stock.

Asus, in fact, may have gotten the memo — and shredded it. Even if this Linux PC doesn't become a mainstream hit, rivals are certainly taking notes.