I've learned quite a bit from Greekchat. For instance, I would never have known much about alumnae initiation, or that it is even an option for someone who isn't an immediate relative (mother or grandmother) of a sorority member.
I also like learning about other groups from all over the country, and how Greek life is at other campuses.
For instance, I just assumed sorority rush everywhere was as hypercompetitive as IU's, so the concept of "everyone who goes to prefs is guaranteed a bid" and high percentage of rushee placement is a bit foreign to me.