Tablet PCs have been bitter pills for Microsoft

Microsoft's demonstration Wednesday of "Slate PCs" made by HP, Pegatron, and Archos was by no means its first involvement in such a form factor.

In fact, the Tablet PC has long been an unrequited love for Bill Gates, who showed the first Tablet PC prototype in 2000 at Comdex in Las Vegas. Here's a look back at other tablet tries through the years.

Source:
http://www.networkworld.com/slideshows/2010/010710-microsoft-tablet-pc.html#slide1