Do you garden? Maybe you even compost? Put those used coffee grounds and tea leaves to work!
Coffee grounds are great in the soil, in compost, and in worm bins. In fact, you can even mound up some coffee grounds around a plant that slugs love and it will help keep them away since the coffee grounds are acidic and abrasive. ( Read here for more info on coffee in your garden. )
Don't forget, you can break open those k-cups and use those grounds, too!
Tea is much the same. You can use the moist tea leaves in your compost bin to speed up decomposition, or mix with soil/sprinkle on soil of acid loving plants like tomatoes. ( Read here for more info on tea leaves with different types of soil. )
We break open our tea bags, but you can also compost the tea bag depending on what it's made of.