To keep the price the same on both models, Asus has given 12GB of storage space to the Windows XP version and 20GB to the Linux version (Linux is free, whereas a licence fee is payable for Windows).
The 12GB is made up of 4GB onboard memory and an 8GB flash module that goes in the card reader.
There's no doubt about it, the Eee PC 900 Win is a fabulous little machine. But at £329, the bargain factor is seriously diminished. Read our full review
No ultra-portable since the original Eee PC has been greeted with quite such excitement as HP's offering; the 2133 Mini-Note.
The company insists that the Mini-Note has been designed primarily for education, but clearly there's more about this little machine than just schoolwork.
Take the curvaceous magnesium alloy shell, the near full-sized keyboard or the stunning high-resolution glossy screen.
In order to bring the product to market as soon as possible, HP has opted to use VIA's single-core C7-M processor; a processor family as sluggish as it is dated.
The UK seems to have been dealt a poor hand with the Mini-Note; while US buyers can choose from a number of customised editions, our choice is simply 'Linux' or 'Windows Vista'.
For us Brits, there's very little reason to opt for the latter; the processor is the same paltry 1.2 GHz chip as the Linux version, with no sign of the 1.6 GHz model in the UK.
The UK editions are still very capable sub-notebooks, but as upstanding British citizens, we can't help but feel a little cheated. Read our full review
First in the 'ones to look out for' list is the Everex CloudBook.
We first glimpsed the Everex CloudBook at CES. It'll go on sale for around £200 and so is directly comparable to our Eee friend.
It's based on a VIA reference design, uses its 1.2GHz C7-M ultra low voltage processor and promises five hours of battery life – significantly more than the Eee PC.
What's more, there's also 30GB of internal storage and 512MB of DDR2; nice specs there. Like the initial Eee, it supports Linux. 802.11b/g Wi-Fi is also on board – but what's up with that weird raised screen.
And how about the Acer Aspire One?
The Aspire One looks like a formidable prospect, especially given its £199 price point for the 8GB Linux version with 512MB of RAM.
Acer has engineered a bespoke interface, rather like Asus' for the Eee PC.
Open Office is offered, as is a Messaging app that can handle MSN/Windows Live, AIM, Yahoo and Google Talk.
Likewise an integrated email app can handle various accounts including Google Mail, but not Hotmail.
This one will make an impression on the market, that's for sure.
The £199 Linux offering is impressive and pound-for-pound the XP version is better value than the MSI Wind.
Acer clearly wants to make an impact – the company will hope the Atom will give the Aspire One the springboard it needs.
Next comes the Dell Mini Inspiron.
It was leaked on the Dell blog earlier in the week and should be officially unmasked at Computex any day now.
The machine is currently rumoured to feature an 8.9in screen, an Intel Atom processor and choice of XP or Linux Ubuntu operating systems.
It also seems the machine will have three USB ports, an SD card reader, VGA output, and Ethernet connections.
Dell is clearly going up against the Asus Eee, MSI Wind and HP Mini Note in the burgeoning budget sub-laptop market.
Fourthly we have the Elonex One. 'The UK's cheapest laptop,' says Elonex's website. It's not wrong.
The One's best facet has to be its price – a mere £99.
If you've a long-standing awareness of IT you might be aware of Elonex as a UK-based business PC provider and latterly for its LCD TV-based range of Lumina Media Centers several years back.
Meant for education and designed with UK Government initiatives in mind, the laptop was shown off at this year's Education Show which took place in Birmingham at the beginning of the month.
The Linux-based sub-notebook has a 7-inch display, 802.11b/g wireless, 1GB of memory, four-hour battery life and even an optional rubberised skin.
What more could you want?