I played through Uncharted Golden Abyss over several days in 15- to 30-minute sessions on the toilet. For the camera function, where you have to point the camera at the sun, I had to stand up to get as close as possible to the overhead light.
I did split shifts at my old job so I had some time to kill in between them.
Trouble was, when playing the same titles at home, I began to associate them with work, which was pretty depressing so I refrain from it these days.
I used to be a service engineer working at airports. Some days I'd be busting my ass and working OT, other days it was pretty slow with time between calls. DS and 3DS were perfect for that. It was especially fun carrying the 3DS around and getting street passes from all over the world.