I practically have a Master's in this subject (4 years in a small chapter at a small school)!
ZE used the bumper rotation method, it works like a charm because you don't need a lot of people to get a group to a good size for conversation.  They are a chapter of 15 (some Midwestern chapters are small 

 ), and invited some members from X (Minnesota) to help them out.  They did exactly what Barbara's group does.  I think ZH may be doing something similar in the fall.
Loyally delsigmata
KSG