I like to lay flat on my back - with my 14 month old son napping on my chest - watching some tech presentation video (or browsing, or even playing the LASW RTS. These are sublime moments that my laptop can't bring me.
It's never been something I had given much though to. The idea of craning my neck and reaching my arms to operate a laptop on the table beside me strikes my as uncomfortable, though.
To each their own, I guess.