Pick up some heavy gauge wire at your local hardware store and make some hanging lanterns.
Just wrap the wire around the neck of the jar a couple of times, then make a loop up for a handle and then around the neck a couple more times to secure it. Add a candle and you've got a great rustic lantern.
Speaking of candles, if you're interested in making your own, canning jars are the perfect vessel!
You can make a terrarium from a canning jar. Add pebbles to the bottom of the jar, then a layer of charcoal, then some soil and finally the plants.
The pebbles allow the water to drain from the plants but remain in the jar for moisture when it's needed!
How about a soap dispenser? Drill or punch a hole through the lid of your jar big enough to slip a pump assembly through. Use a cork on the underside with a hole drilled through it to hold them pump in place and you're all set!
Some cool uses for canning jars that I hope you will try for yourself! I'm Mrs. Fixit and it's just that simple.