cellio's journal made me want to write about Shmini Atzeret. After all, Rosh Hashannah's in a few days (I'm still a bit in denial about this, since Joy's going to her parents and I have made very few plans for the holiday).Shmini Atzeret is a strange holiday. First of all, it's not one of those new-fangled holidays which have only been around a few thousand years, like Purim or Hannukah. Nor is it one of those really new holidays like Yom Yerushalim, Israeli independence day, or something. Shmini Atzeret is in the Torah. It's been around for a long time...
The problem is, it's not exactly clear just what it is. It's right after Sukkot (a harvest festival where Jews build temporary structures, eat in them, and wave bits of foliage and produce around), but it most definitely is not Sukkot.
It's also not really Simchat Torah, which is a joyous celebration of the end of the Torah reading cycle. (This is the holiday where the very end of the Torah is read, and then immediately afterwards the very beginning. Usually from a second scroll, because it takes a while to rewind.)
Shmini Atzeret... is.
There's no particular food requirement (like Passover) or even food custom (like that of eating dairy on Shavuot, the holiday of the giving of the Torah). There's no particular location requirement (during Sukkot, one should eat meals in a sukkah). One may eat in a sukkah, but it's optional.
I heard a description once of Shmini Atzeret which I like. If you think of things logistically, Sukkot was one of the 3 pilgramage festivals where people went to the Temple in Jerusalem. Probably people went a bit early, to get there for Rosh Hashannah. By the end of Sukkot they were ready to go home; Shmini Atzeret is God's way of keeping the people in Jerusalem just a little bit longer.
Arthur Waskow suggests in Seasons of our Joy that Shmini Atzeret is actually a fourth pilgramage festival, corresponding to winter. But the problems of travel in Jerusalem winter caused the festival to be moved earlier.
Shmini Atzeret is a quiet holiday. It's one of the times that Yizkor (a prayer remembering those who died) is said, and the 'additional' reading is Kohelet (AKA Ecclesiastes), which is a bit of a downer.