ForeverDiamond, it looks like the Greek system at Wichita State University made a real attempt to build Greek unity and get the campus to know the Greeks better with their recent Greek Week. There's an article in the student newspaper at
http://www.thesunflower.com/web/isite.dll?1063172588179
Some of the things they did: a clothing drive, blood drive, open houses, etc. Alpha Phi and Beta both have chapters there, so their chapters at your school might be able to get more info from them if the ideas sound interesting. I believe a new membr of Alpha Phi there posted her rush story on GC six weeks or so ago, too. Although Wichita State is a fairly large school, its Greek system is relatively small, so some of what they did might mesh with concerns at your school.