I've recently discoveredMathtrain.TV. It's a website full of videos that kids have created to teach math skills/concepts to other kids. After reviewing several videos on the site, I've been impressed by the level confidence and understanding that some of the kids demonstrate. I feel very strongly that students need to understand the math they're learning rather than just being able to perform steps that lead to a "correct answer". One of the things I like most about this site is that some of the students really do demonstrate number sense and understanding in their videos. The problems I've viewed have all been rote and skill-based, but the way some of the students explain their thinking makes them worthwhile for helping students learn skills.

Via Kristi Grande