You already know I am wary of online social experiences for kids. I worry about what virtual living does to the real lives of those who indulge. Because I am an idealist, I believe children, and adults, are supposed to be striving for honesty and excellence in their lives most of the time. It's hard to be honest in a virtual world, where things don't really matter, and experiences, especially dubious ones, go unnoticed by people who really matter -- parents or other moral leaders. Places like Second Life and There, because of their nature as places that don't really exist, worry me.
Virtual reality communities are unreal places where people make things up and apply this fiction to a persona, which kids may or may not be able to differentiate from their true selves.
I believe this fosters, without exception, an attitude of ambivalence and a way of disengaging in real emotions and life in children and teens, especially when the virtual life is better than, more fun than real life.
As parents, we want our children to be engaged in real living, to really be at the table with us when we are dining, to be present in the conversation when we are asking them something, and to feel and think real things in response to real events.
The way to insulate children from this kind of virtual disengaging from real life is to really have your child's heart. Be more fun, more positive, and more engaging than a virtual world. Every day.