First, we tried out the CD on a long drive. It was an immediate hit for me because the songs have a fun beat and the words are clever and funny (kind of random but that's how that band tends to be).
Then, we tried out the DVD, and it was an even bigger hit with all of us! It's just plain fun, and some of the songs are down right hilarious. My son really likes it. In fact, a couple days ago I was having singing time with him and he requested we sing the "Zero Song." And, after watching the movie and hearing the songs only a handful of times, my son is already better at his numbers. I highly recommend this CD/DVD. They also have one that's called "Here Come the ABCs," which I'm sure is equally great.
For those of you that watch the Disney Channel (we're kind of in the dark ages- we only use TV for movies) you might already know about these songs. I think that's where they originate from. At any rate, they're really fun and a good educational resource.