[Drolefille]

Hope you don't mind the crash but some COB things we've done are:

Dinner before chapter (not in a house, on campus) - easy to get lots of sisters to go
Movie night at a sisters apartment
Cook out with a fraternity (that we were encouraged to 'bring a friend' to)
Visited "Crown Candy Kitchen" a local place that made old fasioned malts and homemade candy.

We made COB events any time there were a bunch of sisters and a potential new member. If a bunch of sisters were going somewhere, you were encouraged to invite people along. They didn't have to know that it was a COB event.