Colleges and Universities have a student activities fund that is split among the recognized groups on campus. If your group is recognized, this can be a relatively easy way to get money. Check with the Student Activities Board for information. This could raise some money as well. This involves getting people to pledge a certain amount of money for each mile the participant in the event walks or bikes.
People can also donate a set amount of money instead of making the per-mile pledge.
Holding an auction where friends of your group donate art work, services, or even handmade goods can also lead to a good fund raiser. The key to this is to have people donate their goods or their time. Call and visit individuals who might want to support your group. Look to past contributors, alumni, or members of the community who might be sympathetic to your goals and ask them for some financial support. Going door to door to faculty offices and dorm rooms can prove successful.