Microsoft upstages Apple's tablet HP Slate with an Amazon (AMZN) Kindle version

Steve Ballmer demos an HP "slate PC" at CES and steals a bit of Steve Jobs' thunder

Steve Ballmer's keynote at the Consumer Electronics Show in Las Vegas Wednesday night ran for more than an hour and a quarter.

But what got the most attention from the press gathered to watch it were the three minutes Microsoft's (MSFT) CEO spent talking about his answer to the tablet computer Apple (AAPL) is expected to unveil in less than three weeks.

Ballmer displayed three versions of what he called "slate PCs" running Windows 7 — one from Pegatron Corp., another from Arcos, and a prototype from Hewlett Packard (HPQ) that Ballmer says is coming "later this year."

In a subtle dig at his competitors in Cupertino, he demoed the HP Slate with an Amazon (AMZN) Kindle version of Stephenie Meyer's "Twilight." The book's cover shows a pair of hands cradling an apple.

You can watch Ballmer's full keynote here. The slate portion begins at the 49:30 mark  .http://www.microsoft.com/presspass/events/ces/VideoGallery.aspx