Share 'Which video sites does your school block/not block?'

I'm interested in outsourcing a bunch of hosted video to a YouTube/Vimeo/Blip.tv-type site, but I know many school firewalls block these services. The materials aren't for kids or for classroom activity; they're for teachers and administrators for purposes of professional development. That said, I'm wondering if those of you who are teachers can help me pick a video service that would be more lik…