Even though incandescent lightbulbs are being phased out in favor of energy efficient CFL and LED bulbs, many of us still use the old fashioned bulbs until they burn out. When they do finally burn out, don't toss them in the trash; donate them. The nonprofit artist group CLOUD makes interactive sculptures out of steel and used incandescent lightbulbs. The sculptures are suspended clouds made entirely out of bulbs and are set in major cities all over the world. Their work uses incandescent bulbs -- not CFL bulbs -- and each installation recycles about 5,000 old bulbs. To learn how to donate your old incandescent bulbs, go to incandescentcloud.com.