Aha! It occurred to me that I might be able to play PAL encoded DVDs on my Mac (an old Powerbook). It's true! As a result, I can now rent Bergman PAL DVDs from Scarecrow Video, to further complete my mission to see all of his films.
I've switched from using the OS X-supplied DVD player, to VLC, which runs on many platforms. So far, I'm very happy with it, though the Mac version doesn't seem to have a single frame advance feature (yet).
To start, I rented Summer Interlude, which I like quite a lot. Here is the lead, Maj-Britt Nilsson:
I also rented It Rains On Our Love, which I also liked very much. Here are the two leads, Barbro Kollberg and Birger Malmsten (who is the male lead in Summer Interlude, too).
It seems now I have seen 26 Bergman films, with a definite 15 left, not including TV productions (of which there are quite a few).