Is your school or club located in an area where car parking is in high demand outside of school or club hours or over weekends—near a major sports stadium perhaps? Rent out those empty car parking spaces for special events.
Another great weekend fundraiser is a car wash. It can be fun for volunteers too (although not so much on a cold day!). Set a fee, find a venue with good drive-by visibility and prepare posters. With car cleaning chemicals and cloths, you no longer need to be restricted to somewhere with hoses and drainage either.