Breaking Through the K-12 Firewall

I've been talking about Web 2.0 for two years, and every school I've shared with has the same concern: How could these applications be allowed with the current restrictions in their Acceptable Use Policies? There is a real fear of breaking out of the box and allowing full access to social networking sites, and most of the schools in my area don't know how to address this. I think they want to provide access, but there are concerns about child safety.

Any ideas?