With Quikrete and this creative how-to, you can grab a few plastic bottles from the trash and use them to make luminous (and low-cost!) pendant lamps that will spice up any interior. Nestle a smaller water bottle inside the top of a two-liter soda bottle to construct the form, then thread a metal tube through the caps of both bottles to create room for the wiring. Mix up some Quikrete 5000 Concrete Mix, fill the cavity between the bottles, and let the concrete cure for 20 hours. Then, all that's left to do is wire the lamp, and you'll have brightened up your home—and your day.