Mason jars have infinite uses! My personal favorite use for them is for indoor/outdoor lighting- dinner parties, barbecues, any opportunities where you can experiment with lighting. They really offer endless possibilities, and the best part is you can usually by a case of them incredibly cheap, or find them at secondhand stores, or even for free on sites like Craigslist and Freecycle.org. Some uses:
As a vase, or planter (Possibly in the kitchen to grow your own herbs…)
To serve drinks, or make your own moonshine
For crafts, or to store your craft supplies
To store spices
To store food: Homemade jams, salad dressings, really anything
As indoor or outdoor lighting: Perfect for candlelit dinners, as well as to light garden paths at a patio party.