The old OUT in Linguistics mailing list seems to have died, so I’ve created a Facebook group for this purpose:
The group is open to lesbian, gay, bisexual, dyke, queer, homosexual, trans, etc. linguists and their friends. The only requirement is that you be willing to be out to everyone on the list as lgbt(-friendly); it’s sort of like wearing a pink triangle.
It’s a “closed” group: anyone can see the group, but only members can post and see the postings.
I’m in charge of adding people to the group; mail to me at firstname.lastname@example.org.
(Yes, you need to have a Facebook account.)