Last year, our chapter paired up with a fraternty. We hung out together that evening, and worked together on the banner that was a part of the overall competition Dance Marathon holds. (Around here, just the word "competition" is enough to get Greek groups excited. The notion of beating other Greek orgs is quite appealing.) We also think of it as a really long sisterhood event, which is fun.
Our philanthropy chair also started a month before Dance Marathon harassing... err, encouraging
all non-dancers into committing to a time to visit those of us who were dancing. The morale boost for us was great and a several of the non-dancers got a taste of what it was like and want to do it again this year.