How thin is too thin for a notebook?

I don't know about you, but my view of razor-thin notebooks has been permanently changed by MSI, thanks to a creative (and supremely twisted) viral advertisement that began circulating earlier this month. Because of this, my colleagues and I jokingly refer to this as-of-yet unclassified style of ultraportable as "cracktops."

Of course, within the industry, what I would refer to as a "cracktop" seems to be increasingly falling into "category X." Both Lenovo and MSI call their ultra slim portable lines the "X-series," and Sony today unveiled the Vaio X, which would fit right in among the others. (UPDATE: Samsung has just revealed its own slim notebook, also to be called the X series.)

The Intel Atom-powered Vaio X that Sony showed off today is built of carbon fiber and aluminum, is only about half an inch thin and weighs only one and a half pounds. If these measurements prove to be accurate when Sony officially releases specs in October, it will be the thinnest, lightest PC on the market.

Here's how the Vaio X series stacks up against its competitors in the form factor:

• Asus Eee Seashell: 1.01"
• MSI X-series: .79"
• Macbook Air: .76"
• Lenovo X-series: .75"
• HP Voodoo Envy 133: .70"
• Dell Adamo: .65"
• Sony Vaio X: .5" (unofficial)

For those keeping track, the Vaio X when closed would only be .14" thicker than the Amazon Kindle 2.

Since it's a Vaio, and since it will offer cutting edge (no pun intended) slimness, everyone expects it will cost a bundle. We contacted Sony today to see if it would be releasing any information about it in print today, but company said it is not going to comment on product roadmaps. Engadget was told today that it will be available about one week after Windows 7 launches, which would mean on or around October 29.