My campus recently hosted a Panhellenic fundraising event that also counted for service for the women who participated! Volunteers from PHC + all of our sororities made grilled cheese sandwiches. All of the money we raised through the event went to a local charity.
Flyers, an email, and a campus sign were distributed about a week before, stating that one could buy a grilled cheese & have it delivered anywhere on campus for $1. You could get multiple sandwiches for increasing price increments of .50 cents, I think. (ie: 2 = 1.50, 3 = 2, 4 = 2.50 and so forth.)
Sorority women worked 30 minute shifts between 9pm-12am in kitchens in the dorms; the total event lasted from 9pm to 12am, when a ton of students were hanging out in their dorms or the library. You could call the cell number of the PHC officer in charge to place your order, or email them using the address on the flyer for an advance order. During the event, women who were there, but weren't cooking sandwiches at the moment went to Facebook and Twitter, posting details about the event and encouraging people to order.
I'm from a smaller campus, but it's certainly something that could be scaled up for a very large campus. You'll need a good amount of workers to keep up with the demand that would likely occur on such a large campus, but if there's women in need of service hours, it was an easy way to get an hour. Incentive to get people to join up, if needed.
Hope that helps!