I'm one of the VPs of my professional fraternity. It's coed and we have a ton of people involved b/c we do business stuff, community service stuff, and of course, lots of social things as well

The problem is - there is a HUGE rift between our members. The fraternity is dominaed by social greeks (like XOs and EXs, etc) and the people who are not social greeks often feel left out. There are tons of cliques. We also do a lot of the social greeks philanthropies, overall we're a very pro greek organization.
Does anyone have any suggestions of what to do about this? Any games or team building activities we can play to break the ice between members and get everyone to know each other better?