I don't usually do anything while on the toilet besides number 2. I would bring my laptop or a book if I did, but I'm not usually on the toilet long enough to read or do anything on the laptop.
This is some thread! Sure makes me laugh though... I never stay in long enough to much of anything. Staying in the facilities for longer than ten minutes is a waste of time.
Sometimes a person is just too tired or lazy to get up after one is....finished. Sitting for too long can make one's legs go numb, and that can often destroy the motivation to go anywhere.