Our group plays on tennis courts and uses temporary nets. With a group box, the first people to the courts in the morning can set up the nets and we don't have to worry about who stays until the end since anyone can put them back.
Gone are the days of lugging them to/from our cars, and taking down nets when someone leaves just to set up a different one. It's a small addition, but one that's shown immediate value.
We don't take dues, so we just passed a hat and quickly raised the funds needed for the box, paint, locks, anchor hardware, and extra keys.