From Mobile PC Wiki
"I think the Tablet PC platform is a winner because ...
It is for me the most transparent computing technology in my computing cluttered life.
It allows me to:
To do real work without having to focus on the technology. When I do this in the presence of other people (after the initial oooh-ahhh phase), the technology does not intrude on interactions with the other people. Instead, it usually enhances it. When I lecture walking around with my Tablet PC, what I do on my screen, including inking shows up on a projector or participants machines, in real time. This elicits a certain amount of wonder at first, but becomes normal very quickly. Portability: To the extent that having a computer handy is a good thing, it is a very good thing to be able to have this handy just about anywhere.
Transparent Computing can mean many things so I've included links at the bottom to a couple of thought provoking articles.
An interesting interpretation of the term suggests that some technologies mature, becomes ubiquitous and so pervasive that they cease to draw notice. They disappear.
Pop quiz! What is the order of the colours of a traffic light?
In a few years, the pen and ink interface may be as commonplace as a mouse. I expect that for most people new to computing technology, the pen will become transparent far faster than keyboards and mice have in the past.
How will we know that Tablet PCs have “arrived“? Don't give it a second thought. Nobody will notice.
Where Have All the Computers Gone John Seeley Brown