Compost
Add used coffee grounds to your compost, worm bin, or municipal compost service. Coffee is a “green” (nitrogen-rich) material, so add “brown” (carbon-rich) materials for balance. Un-brewed coffee can be composted.
Fertilizer
Coffee grounds are granular, slightly acidic, and high in nitrogen. Sprinkle them onto the soil, or work it in. Use only spent coffee grounds. Un-brewed coffee is too acidic and nitrogen rich, and can burn your plants.
Deodorizer
Rub coffee grounds on your hands to remove smells like fish, garlic, and onions.
Dye
Soak white paper in water and used coffee grounds for an antiqued look.
Meat Marinade
Use a small amount of freshly ground coffee in marinades as a tenderizer for beef.