Hi everyone!
I'm encouraged to see a few people talking about mentoring, and our group will certainly try to support that however we can. Our organizing committee has thought of doing a few other things we saw in CodeRabbi's talk, such as a dev book club, but haven't had a chance to put anything together yet. Hopefully we can organize something(s) this summer. Definitely let us know if you have ideas or would like to see something in particular.
For those interested in mentoring or being an apprentice, take a look at
http://phpmentoring.org/. They have some good tips and guidelines for mentors and apprentices to help ensure a good two-way relationship and that both sides benefit. That's an important factor and mentoring shouldn't be thought of as just "free training". I've known many people who started out as apprentices or mentors, which led to great friendships, fun projects, community recognition, and even job offers, so it's definitely worth the time and energy.
Elizabeth Smith has done a great conference talk on mentoring, so there are some tips for beginner, intermediate, and advanced developers (buried among tons of cat photos) at
http://www.slideshare.net/auroraeosrose/mentoring-developersphp-benelux2014.