I found this interesting YouTube video via the "Perfect Patterns" Yahoo group. It describes a fast, tidy way to sew on buttons and snaps.
Even though I was taught as a young child to sew on buttons (part of a badge requirement in Brownies I believe), and then reviewed the procedure in a high school sewing class, and then again in a college Fashion Design program, I was never shown, nor did it occur to me, to use multiple strands of thread in the needle to accomplish the task in short order!
The only thing I disagree about is the large knot ball the instructor starts with. I was taught, and I believe it is much tidier, to start the thread on the right side of the fabric with several small stitches to secure the start of the thread rather than a blob of a knot.