http://youtube.com/watch?v=Jj5BL-tVIpM&feature=related
I am teaching my children that religion is dangerous & stupid in the same way as beating your head with a brick is dangerous & stupid.
If as an atheist you honestly believe religion is dangerous to your kids you have a responibility to teach them this, in the same manner as 'sticking a knife in a powerpoint might kill you'. You also have an obligation to teach them analytical thinking so that they can determine their own beliefs, & hopefully reach the same conclusion.
As a theist, if you believe your child will go to hell if they don't embrace your god then you likewise have a responsibility to teach them your religion. You should not teach your children analytical skills as this will endanger their choice to follow the religion.
However both atheists & theists have a moral obligation to determine what they believe with evidence prior to teaching their kids. I would not attempt to teach my kids how to fly a plane as I have no knowledge in this area. Similarly I have no knoweldge of a deity or what he may expect from us, & I submit that theists also have no such knowledge, merely a belief that is impossible to justify. The evidence is that religion has & is likely to continue to harm millions of people, & I desire that my children not be amongst them