Our Alpha chapter holds an informal Rush picnic midway through the summer. And I don't remeber what it was called, but I remeber someone saying they had some sort of weekend daze (might not have been during the summer and i'm not sure if they still do it) where guests were welcomed into the house for movies and to stay in the house overnight so they could get a better feel of the sorority.

In the past, My chapter (Beta) held a few informal events from picnics to Shakespeare in the Park. (A troupe was putting on a production about once a month and those around tried to bring friends and go watch the play.)