Well, here's what I do (and have done) as a Gamma Phi Beta alumna, and only since 1999. And, no I'm not bragging, but you were wondering what there is to do. Now, fraternity involvement might be different, I don't have any first hand knowledge to add.
Founding President, Puget Sound Alumnae Chapter 1999-2003
Convention Delegate, 2000 & 2002
Helped reorganize the Gamma Epsilon House Corp Board
Gamma Epsilon HCB Treasurer, 2001-present
Gamma Epsilon Scholarship Advisor 2003-present
Chair, Badge Task Force, Fall 2002-present
International Nominating Committee, 2002-2004
I'll also have another IO position after I'm finished with Nominating Committee. My local support is not as much work as it sounds either, I also take part in Senior Celebration and some other events at the collegiate house.
I think if you look, you will find that there are a number of ways that you can help out a collegiate chapter. My collegiate chapter has only recently gotten advisor support, they had none for MANY years.
No wonder, I sometimes feel like I bleed brown and mode.....