Me and two other photographer have been established in 2009 a group that contains only square frame and monochromatic photography. It'd be our honor if you take a look at it and join it! It's really a great opportunity to catch up with great photographers in 500pix with out group.
Feel free to join the group and if you have any additional questions about submit your work and asking about the rules!
Here is the link: http://mono-square.deviantart.com/