Slack
Noisebridge has a team on Slack. We use Slack as a glorified IRC, with multiple rooms to discuss different topics, often separated by working group, such as SecWG or CommunityWorkingGroup.
Slack is accessible on the web, as well as via IRC or XMPP clients.
Unlike Noisebridge's IRC channel, Slack requires an invitation to join. Below is a (currently empty) list of whom to contact to join Slack: