If you have White Lily flours available in your area, Shirley Corriher swears by their self-rising flour. Her comments on the advantages: chemical leaveners work best with lower-protein flour, so you're getting a flour that's going to give you a much more tender product; White Lilly has a well-earned rep for having great milling consistency like King Arthur does; millers have access to a much greater variety of chemical leaveners than the regular consumer, so they can better control the leavening phases; and self-rising flours have a perfectly uniform blend with the leaveners well-dispersed through the flour for even baking results.

Great! Thanks everyone for your help!

I know that a lot of asian grocers [like my Ranch 99 in Irvine] sell 1kg bags of self rising flour so you you won't have to make a 5# commitment.

We always used Martha White Self-Rising Flour when I was a kid, and Mama made biscuits every morning and most evenings. She'd have all-purpose on hand for yeast breads, sweet rolls, etc. I don't make biscuits nearly as often as Mama did, so I use the A/P and add baking powder and salt. Or baking soda and salt, if my hand lands on that box first. I can't tell any difference.

Per Harold McGee: "Self-rising" flours are flours that contain baking powder (1 & 1/2 teaspoons per cup flour/5-7 grams per 100 grams).

If you have a recipe that calls for self-rising flour -- I just got this info myself (instead of virtuously bypassing the recipes):
for one cup, 1 cup all purpose flour + 1 1/2 tsp baking powder + 1/2 tsp salt.
I would then watch the total salt in the recipe, and if acid ingredients like buttermilk are called for, remember that baking soda is usually added to balance them.

Yeah, I've always kind of thought that self-rising flour was a ridiculous idea. But I have a coconut pie recipe that I'd really like to try that calls for self-rising flour (!) and it seems to be a fairly integral ingredient, so and I'm trying to figure out what I can use instead to get out of purchasing any.

Most bakers and pastry cooks disdain the use of self-rising flour. But there are doughs that do require a chemical leavening agent (not yeast). Unless you are planning on making a 5 pound bag of the stuff for a single type of baking I don't see how it's worth the time.