How and when should a child be introduced to Buddhism? My son will be four soon.  I would like to introduce him to Buddhist philosophy, and some meditation practices.

However, stillness is, at this point, completely foreign to his personality :)

My wife is Christian, and has taken him to church a few times, but not regularly, or recently.  She and I are okay with sharing our differing beliefs with our son.  

I'm not active (or aware of, really) any local Buddhist groups, and, unfortunately don't even meditate regularly anymore.

Still, I think meditation, and an understanding of the philosophies, would be very helpful to my son, and I'd like to get him involved as soon as is practical.

How do I best introduce him, both to meditation and Buddhist philosophy?  At what age is he likely be ready for either?
I have a daughter who is nearly 4 now. I first took her to the local Buddhist Centre when she was about a year old on a family day that we organised. The Buddhist practice involved running around the shrine room and shrieking. Someone said at the time though that bring her at such a young age was auspicious and I'm enought of a romantic to lap this up. I took here again a few months ago and her Buddhist practice is much the same - running and shrieking. But we all enjoyed it and she's had a positive experience. 

As far as meditation goes. Mmmmmmmm, She decided to have her first meditation a week ago. I think I timed 5 seconds. Better than I thought it would be. I have to say my local centre doesn't really teach meditation to people younger than 16 but I think that more of a guardianship issue rather than the impossiblity of younger children meditating. I've been in meditation sessions in festivals with 12 year old and they seem to get on fine. 

I don't really have much more advice - just my own experience. I have to say though I agree with Richard Dawkins (though i have to say not in such strident terms) in that children should be old enough to chose the religion they belong to - not just inducted into it. However I believe that Buddhist ethics, Buddhist stories and a little bit of an understanding that's its OK just to be a little be quiet now and then, would be good for any child.

Generally being kind to yourself and kind to others is what I want my daughter to know and if that's in a Buddhist framework then fantastic. We are going to go on a Buddhist family retreat in North Yorkshire (UK) so we'll see how it all goes there. Wish us luck!