I think we mention this in Grassroots, but maybe you could have a day that your cafeteria is vegetarian? Or you could do a visit to the shelter. Having done some research on this, I realize that there are two main problems:1) As much as people want to "save animals" when it often comes to getting their own animals, they overlook the shelter and get more "well-bred" animals. We need to get people into the habit of going to the shelters. 2) The reason that we have an abundance of animals is that many people don't get their animals neutered. I think that we need to do outreach into poorer communities and let them know them know that most shelters actually provide this service free of charge.
I think that you could do outreach on both of those points. I think a key to successful fundraisers is to make it something new and different and also make it tangible. For instance, eating vegetarian for a day or take your pet to the shelter day or something that people can grasp and that has clear goals.
I hope that gets you thinking. Let me know if you have further questions