Technolanguages is a site I have belonged to for a while, but had forgotten about it!  Sometimes, I take workshops, find something that I become very interested in, sign up and then never log into it again.  It's probably a side effect of my vida loca... :)  It's expanded a little bit since my last visit, but it doesn't appear that the forums are any more active than they used to be.

Spanish Teacher Chatboard is another place I use to connect to others in my field.  The chatboard takes on a couple of different tangents: one is the "newbies" asking for advice and the other is discussion about how to approach different topics within our common levels.  I like this particular site because one can take a look and discuss theory and practice as well as connect on grade level and find out what topics are trending in the field.

I can't say that I contribute much to these boards, I mostly lurk with a purpose in mind.  At this point in my career, I feel more confident beginning a thread or contributing my ideas to add to a discussion.  After all, I'm always willing to learn something new!