Ask HN: Which CTO peer groups (online) do you recommend?

I'm a CTO in Cebu, Philippines. For my and our company's growth I want to surround myself with many peers, other CTOs and technical leaders that are more experienced and much better than me. That have seen the same problems and have mastered them. That can mentor me.

Devs do that via meetups, SO and the likes, so I've co-founded a local meetup for tech leads. We're now a happy bunch, sharing and meeting regularly, and I'm learning a lot. Our setup is a bit peculiar, though: social startup, global market, a single quite complex product. This means some questions remain unanswered as there simply aren't all that many CTOs with a similar setup than ours in Cebu.

What online peer network/CTO group/tech leadership mailing list would you recommend to join? Or how else can I identify and fix my deficits quickly?