Since Sony's exceptionally portable notebook line made its debut in the form of the Vaio VGN-UX17GP, the design and features have remained essentially the same, with each successive model being refreshed on a newer platform.

The UX38GN, however, broke new ground as possibly the first notebook with a screen size of under 10 inches to come with flash-based storage. With a battery life rated at over 7 hours using the optional extended cell, this may be the mobile solution frequent travelers are looking for.

Upside: Though technically not an Ultramobile PC, the Sony UX series certainly fits the bill as a notebook with exceptional mobility. When the first-generation UX17GP turned up, its short battery life and hard-to-use keyboard kept it from receiving our stamp of approval. Though the latter remains unchanged in the latest iteration, the improved battery life of 7.5 hours with the optional extended battery (3.5 hours using the standard cell) should see most users through an entire work day. This is due to the use of a flash-based harddisk under the hood.

As flash memory has no moving parts, it is more hardy than its magnetic cousin and also provides faster data access. According to Sony, the increase in performance translates to a 20-second reduction in bootup time.

The 4.5-inch display is of the touchscreen variety, which means you can use anything from the included stylus to your fingernails for navigation or a quick sketch. For data input, a keyboard slides out from below, though it is more accurate to describe it as a thumbboard due to its restricted dimensions. A 1.3-megapixel camera on the back allows for quick snapshots, while a second 0.3-megapixel Webcam sits above the display for video conferencing.

A fingerprint sensor is included for logging into the operating system and a port replicator is bundled with the Vaio. The latter increases the UX38GN's single USB port to a total of four and provides FireWire, monitor and AV outputs as well as an Ethernet port.

Downside: This machine is no powerhouse. Based on the last-generation single-core processor platform, it may not have issues for standard productivity tools like emails and office applications, but will whimper under heavy multimedia loads. The keyboard, as previously mentioned, does not exactly provide a comfortable typing experience. Wordsmiths are advised to connect an external keyboard if required.

At S$4,499, the UX38GN is not targeted at your typical consumer. The Windows Vista Business Edition OS hints at its role as a portable business machine. However, the lack of a TPM security chip and other data protection features make this device unsuitable for storing mission-sensitive data.

Outlook: The paranoid and budget user may have to look elsewhere, but those with deep pockets and a need for an exceptionally portable device will be hard-pressed to find an equivalent to the Vaio VGN-UX38GN. Just make sure you get the extended battery for long trips.