Use them for a deodorizer according to Vision Magazine:
“Deodorizer—Whether you love or hate the smell of coffee, that smell is not an issue when it comes to using coffee grounds as a deodorizer. Coffee grounds attract and trap unwanted odors, without imparting that unmistakable coffee scent.”
Also you can use them to clean your sink drains:
“Keep the kitchen drains smelling fresh — Do you ever walk through your kitchen and smell a foul odor, only to discover that it is emanating from your drain? You can use coffee grounds about once a week to remedy this problem. The first step is heating some water to a boil in either a teapot or a pan. Once the water is hot, bring it over to the sink. Pour about a half cup of used coffee grounds down the drain, immediately followed by the hot water. You should follow the coffee grounds with at least 5 cups of boiling hot water. The hot water will push the grounds through, ensuring that they will not clog the drain. Your drain should smell fresh for at least a week afterward.”
For other neat ideas on what to do with coffee grounds see this article.