Next time you brew up a pot of Joe, don't just toss the used grounds. Instead, put them to work again. Sprinkle a layer on top of the soil of your house plants! They act as a natural fertilizer and insect repellent. You can also use them on your out door plants. Check with your local coffee shop (and isn't there one on every corner now?) Ask if they have can give you their used grounds. Most will willing pass them on to you for free and you can pick them up by the bag full!
So how is this frugal? By reusing something for another purpose, it usually is frugal, not to mention Eco-friendly. It also saves you from buying fertilizer and insecticide. Once again, also Eco-friendly as it saves those nasty chemicals from leaching into the ground. Unless of course you buy organic options. Then your good either way! :o)