In "pixillation" the moviemaker shoots living actors's performances one frame at a time. (We'd do it with other animals if they'd hold still for it, but they're too smart for that.) Some animators let the actors control their performances, while others treat the actors as "living armatures" and position them the way they'd position an armature in stop motion animation.
There's a lot of pixillation in Zanymation Magic, which I edited from improvised animations created by the instructors and facilitators at Quickdraw Animation Society's Zanymation animation events. Of course, we're improvising with cutouts and other things as well...
Digital still cameras have changed the making of pixillation animation - for the better. It's technically a lot easier and cheaper than it was with film, but you still need as much imagination as ever. Here's a great example, Ten Thousand Pictures of You, from mrtricks at aniBoom.