I just spent the whole weekend planting a veggie patch in my back garden so I can grow fresh, organic food for myself and my family. This meets several goals all at once. I will be getting more exercise and eating more healthy, vegetarian food. Growing your own food is also better for the environment, as there is no pollution from transport, pesticides or fertilizers, and the plants act as a carbon sink.
My next step is to plant some native plants to help improve biodiversity in my area.