PHP on LinkedIn.com

Since LinkedIn opened up its Groups system, there has been a huge growth in the number of groups related to PHP.  Some with charters, some without; some with a specific community background and others with a specific regional focus.  I am posting this to bring attention to some of them.

In order of popularity (member count) some general groups (non-regional) are:

Some of these are useful if you are looking for a job (the recruiters tend to play nice and stay on-topic), others ban job posts and stick to discussions.
There are literally hundreds of groups related to PHP in some shape or fashion – pure PHP, LAMP, PHP&Mysql, Frameworks, and many regional *PUG type groups.