Little changes make big differences in swimming, or so I'm learning. My swimming education has been frustrating at best, due to my complete inability to find a coach/lessons that work for me. As such, I've had to take my normal approach and read a few books and watch a bunch of videos. I know that isn't ideal, but that's how I learned to Eskimo roll a kayak too. Hopefully swimming with my local tri club will make up the difference this summer.
Anyway, this little change just made a big difference for me as a swimmer. I still have some work to do to get it committed to muscle memory, but I've already gained some swim speed from it!