Is there a simple way to expand multiple cells simultaneously?
At the moment I am primarily interested in fully expanding "in one fell swoop" all the cells in a documentation window, although I can imagine situations in which I'd want to open several cells only one-level deep, so I'm interested in this case as well. Finally, it would also be useful to know how to collapse multiple cells at once.
EDIT: My immediate interest is for ways to do this interactively, rather than programmatically. I.e. keyboard (+ mouse) shortcuts, or (second best), menu commands.