Here are a couple of interesting articles about teaching math:
Math Trek (Nov. 10, 2007) — Spinning a good yarn may seem to have little to do with mathematics, but a new study suggests otherwise. Preschoolers who tell stories that include many different perspectives do better in math two years later than those who stick to one simple perspective. The researchers believe that the study may highlight a deep connection between mathematical ability and narrative skills… [Hat tip: Wild About Math!]
Gesturing Helps Grade School Children Solve Math Problems
ScienceDaily (Nov. 5, 2007) — Are math problems bugging your kids? Tell them to talk back — using their hands. Psychologists at the University of Chicago report that gesturing can help kids add new and correct problem-solving strategies to their mathematical repertoires. What’s more, when given later instruction, kids who are told to gesture are more likely to succeed on math problems…
And that last one includes a link to this article, from awhile back:
Teaching Math Two Ways At The Same Time Boosts Learning
ScienceDaily (Feb. 23, 2005) — Researchers at the University of Chicago have come up with a technique for teachers to use that increases student understanding of mathematics: explain how to solve a problem in one way, and also provide an alternative approach through gesture…
Denise Gaskins' Let's Play Math 
The gesturing study has some real problems with it, in terms of research design, but the narrative one is new to me, and sounds very exciting. And here I am being so lazy that I commented before reading the linked articles.
It seems like most education research has real problems. It must be very difficult to isolate a hypothesized cause-effect relationship and study it, without having all sorts of other factors affecting the outcome.
I’ve taught my DD to write and work her math problems in the air to help visualize them when she doesn’t have paper and pencil handy.