My sister (blood sister) went to Rice University, a small private school, and they do not have a greek system. It is my understanding that the founder of the school, William Marsh Rice, stipulated that the school should never have a greek system. Also, I think my sister said too that each student must sign a form stating that they will not join a GLO off campus while they are a student at Rice U. Instead, students are assigned to different colleges (dorms) and they form bonds within their college. I think there are like 6 or 7 different colleges, all co-ed. So, when it comes to different campus activites, the colleges compete with one another. They seem to have the same kind of fun as being a member of a GLO. One college, Baker College (named after one of the James Baker's, I or II) has a monthly event called Baker13, where on the 13th or 31st of the month guys from that college streak across campus with saving cream covering certain 'parts'. Rice is kinda liberal.
