Just like the walls, all of our ceilings are also original 1920's plaster. I knew the cracks in the ceiling would require repair even before I decided to re-do the entire bedroom. Frankly, the thought of trying to perfectly plaster the ceiling above my head is the reason why I delayed for months on this project.
In searching for a plaster alternative, I decided on beadboard. This was something used in old house ceilings, but typically in bathrooms and kitchens. TOH first gave me the idea to use it in the bedroom Here. I also really liked the sample photos at Nantucket Beadboard and Here.
Home Depot carries pine strips that are 12' long by about 8" wide. A cheaper alternative is the beadboard plywood; however, these only come in an 8 foot maximum length. Since the room is 10' x 12', there would have been seems everywhere.
I did two heavy coats of oil-based primer to ensure that all the knots in the wood were sealed. In some spots I did a skim coat of plaster, sanded, and the coated with Killz primer.
This was definitely a two person job, and one where the scaffold was a key tool. A nail gun made the job much easier.
In some spots the pieces wouldn't come together very easily. A rubber mallet moved things along.
It took about two weeks (tinkering after work) to get the boards cut, primed, and sanded. The original quality of the wood was not as good as I had hoped. Just putting up the beadboard took and entire day with two people.