They are the English Language Support Teachers Association here in Ireland. Their membership appears to include teachers of Spanish and German here in Ireland as well as English Language Support and the occasional EFL teacher (me) and UCC's Séamas Kirkpatrick. There seem to be a lot of links to TCD amongst the Exec group.
I suppose the main reasons to join groups like this are to find out where you live and to find good resources. But the best resources are always going to be people. Despite my love for multimedia, hanging out with sharp people is one of life's great pleasures.
They'll be having another conference in Dublin on the 15th of October. If you come along and read their site first you'll be finding a whole lot of other people who are into what you do. And iron sharpens iron. This is what my grandmother said years ago. Personal Learning Networks is the more recent buzz word for it.
These don't just have to be physical. Twitter really can work for a for you in finding resources and materials and advice from working teachers like ourselves and the people who write our materials. Loads of authors use it to stay in contact and keep sharp. If you aren't using it try it for a month following the people on the list in this site on PLNs.
I think you'll be glad you did.