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.
Among the groups on his list are ones like LinkedPHPers, PHP Technology Specialists and a PEAR group. There's a lot of recruiters that come through trolling for jobs on some while others ban those posts all together - it just depends on the group.