James has recently mastered pulling himself up onto chairs. He'll walk up to the chair and pull his whole body up using basically only his arms. Once he's there he likes to sit for a while like a big boy, and then, when that gets old, he either keeps on climbing (onto the table, for example) or he climbs down and toddles away. Most of the time, anyway. Other times, somehow, he forgets that he knows how to get down. He'll sit and sit until he gets rather frustrated and starts to cry. Those times, he will literally stay there until we pick him up.
The first time I realized this was the case was Saturday afternoon. Paul set him down on the ottoman in his room (which James likes to climb on from time to time). We were both in the room with him, but he turned to us and said "Bye bye!" So we laughed, said "Bye bye" and walked out. And he stayed there. And stayed and stayed. Every time we peeked around the corner of his door he was still chilling there, babbling away. After a good ten minutes of this (at least), James started to get upset, and we ended up going in and rescuing him from his self-inflicted time out.