An easy way to add illumination to the backyard doesn't involve expensive solar or electrical outdoor lighting. All you need are some rocks and nontoxic glow-in-the-dark paint. Collect medium- to large-size rocks in your own backyard and slather them with a few coats of glow-in-the-dark paint. Allow them to dry and create a pathway with the rocks. They'll cast a glow when the sun sets and help lead you and your guests through the dark backyard, free of "charge."