The original, and some would say the best, Pub Standards faction. We would, obviously.
Pub Standards London lounges languidly lapping liquids at the Bricklayer's Arms on the middle Thursday of the month, always announced on Upcoming, but the best way to keep up to date is to subscribe to the Web-1.0-tastic Mailing List where all topics of conversation that do not include beer are mercilessly mocked.
But! Once a month isn't enough for the guzzling geeks of old London town, and so on the fortnights either side of Pub Standards they meet up for the specially named Sub Standards (That's the thursday two weeks before and two weeks after PS, tempomathmatics fans). Because Pub Standards is always in the Bricklayer's Arms, it is Ruled that SS may never been in the same pub twice, so you'll have to follow the list (or Upcoming) to find out when the next one is.
London PS is mostly a friendly lot, unless you like Java, and some can be found on the #pubstandards channel on irc.freenode.net.