The hats are crocheted, actually! =)
I know how to knit as well, but find that I like crocheting much better - it's faster, and more fun in my opinion.
I learned how to do both on youtube - if you're looking to learn, that would be the place to go! It's free, which is the best part.
Ah, I was wondering if they were crocheted, actually... it's tough to knit in the round on such a small scale. A coupe of my friends crochet, though, and they make such cute little things (one crochets sushi filled with catnip)!
Thanks for the Youtube recommendation! I'll definitely check it out.