A few words of advice.....Under no circumstances should you leave your Webook open at work, no matter how much you trust your co-workers.  They WILL edit your profile and mock the things you hold in interest.

Regarding Project Invites:  I will pretty much join any project I am invited to, however I DO NOT have a lot of free time to devote to helping out on projects other than mine.  However, I am interested in seeing what other people are working on and I would like to help out when and where I can.
I don't fancy myself an accomplished writer or some know-it-all.  I simply like to write what I write, regardless if it is "correct" or not.  I like to give suggestions and feedback, what I may suggest may be unorthodox or plain wrong, again I am not an English major or a professional writer.