or an option like "i don't have one and doubt i will take the effort to get one, but if i happened to acquire one i might use it sometimes".
unless the pillow in bed counts, obviously.
i could imagine it being useful if reading whilst eating lunch, as gwynevans said, because i often do this and i usually have to prop my book against *something* (often the bread must do). with pbooks it is especially tricky, because you have to prop it up and hold it in position and keep it open and then try to turn the pages with one hand and avoiding knocking it over... have i mentioned lately just how much i love my eb1150 ?