I'm participating in a photography collaboration group that's currently up and running... Check it out!
ZuperQuirk is 6 photographers from various locations on the globe, creating challenging monthly assignments. The complete information and bios are on the site. Every week there is a new set of photos and every month or bi-monthly there is a featured pdf of chosen photographs. At the end of the year we will publish a book of our work. We're very diverse in our styles so come check it out every week.