I wonder if there's a decent, cheap 9" tablet out there with marvelous PDF support. I tend to like the iPad because the PDF rendering engine is just awesome. It is even better than Adobe's in terms of speed, I think. And the font smoothing is just perfect, and the brightness and contrast of the LCD has no match. I haven't seen a general use LCD screen that beats the contrast of that screen. The only problem here is the price, specially when you want to buy your first decent scope. I guess due to the nature of a LCD screen, reading is also harder.
A cool application for a tablet in electronics is to have multiple PDF's opened somehow along with schematics, online references, etc., but having the tablet stand on the back of the bench, so you can quickly reach it without having to sacrifice too much space as you would with a laptop.