I'm aware of no evidence that theistic belief even helps people be more altruistic.
Note that I'm NOT claiming that atheists are less moral on average.
Right; I agree with you. Theism, in and of itself, doesn't get you anywhere. It does, however, help enable the rest of organized religion. It's hard to take church or whatever too seriously if you're a confirmed atheist. Organized religion, in my opinion, does have many useful and powerful resources for building character. I doubt that getting access to these resources is worth the irrationality, though, so I'm looking for substitute character-building resources.
Other commenters have suggested teaching people about tit-for-tat, collective action problems, etc., but I'm not convinced that game theoretic education can take the place of character education -- you can understand quite clearly how the world would be better off if everyone cooperated, and nevertheless feel that your best individual course of action is to defect around the edges and try to hide it.
Why would you expect church to be good character education compared to, say, television, which preaches a much more modern and sophisticated morality. I suggest Nip/Tuck, or for the young, Kimba: The White Lion and maybe the Ewoks Droids Adventure Hour.
If you want a religion though, there are surely factually accurate forms of atheistic Buddhism.
I've long entertained a dubious regard for the practice of lying to children about the existence of Santa Claus. Parents might claim that it serves to make children's lives more magical and exciting, but as a general rule, children are adequately equipped to create fantasies of their own without their parents' intervention. The two reasons I suspect rest at the bottom line are adherence to tradition, and finding it cute to see one's children believing ridiculous things.
Personally, I considered this to be a rather indecent way to treat one's own children, and have sometimes wondered whether a large proportion of conspiracy theorists owe their origins to the realization that practically all the adults in the country really are conspiring to deceive children for no tangible benefit. However, since I began frequenting this site, I've been exposed to the alternate viewpoint that this realization may be good for developing rationalists, because it provides children with the experience of discovering that they hold beliefs which are wrong and absurd, and that they must reject them.
So, how did the Santa deception affect you personally? How do you think your life might have been different without it? If your parents didn't do it to you, what are your impressions on the experience of not being lied to when most other children are?
Also, I promise to upvote anyone who links to an easy to register for community of conspiracy theorists where they would not be averse to being asked the same question.