Yes I do and it started out with them watching me do yoga. I would do yoga as best I could at home with my kids playing around me and using my downward dog as their tunnel, etc. Eventually they started doing poses with me and asking if we could "play yoga". They enjoyed it so much that I ended up getting them each a mat. We also purchase The Yoga Garden board game and we play that often. I have also been pleased to see that they pull their mats and/or that game out on their own to play together. I have also seen my oldest doing Tree Pose to help himself wait in line and strike a few poses and take some breaths when he is feeling angry. It's been an awesome experience and one I hope to keep going.
I used to do quite a lot of yoga but never really mastered practising it as home by myself. For various health reasons I can't do it any more but it's a good idea to teach it to children - I have vaguely thought about trying to find a yoga/relaxation/meditation class for my son but haven't had a chance to look for one yet! He is a world champion in running, jumping, and other forms of vigorous exercise but could really do with learning how to centre himself and calm down which I think yoga would be very helpful with.