Machines/ technologies?

If books really are machines for thinking and learning, as Umberto Eco once wrote, then the success of the Amazon Kindle suggests the possibility of something rather like mobile learning. And now that you can get a Kindle reader on your iPhone, eReading could become much more widespread. That opens up some new possibilities. My first reaction to reading this news was to wonder about the separation of reading and writing (not ever having used a Kindle I am imagining that there is no writing function). A great deal of my reading, particularly my reading for learning is done with a word processor or pen at hand. I suppose my ideal mobile gadget would be light, with a size somewhere in between a smartphone and small laptop, and have all the possibilities that a good laptop holds.