I have a burnt out lightbulb that's in an open fixture about 15 feet (4.6 metre) high. How can I change it without a ladder or using one of those bulb changer extension arms? I tried the extension arm, but it wouldn't grip the bulb well.
Make a dispensable gripper!
Wrap a piece of duct tape around the end of a long stick, in such a way that you get a kind of cup shape with a sticky inside. Get the idea?
Convince yourself that the tape won't get pulled from the stick after you have pushed the cup onto the bulb and started unscrewing it. If in doubt, wrap some extra tape around the lower part of the cup, to fix it firmly to the end of the stick.
Removing the old bulb will be easy. Mounting the new one is slightly more difficult. Use a smaller cup so the tape isn't wrapped around the bulb but only 'kisses' it.
Lubricate the metal part of the bulb with a drop of oil, WD40 will do, then wipe it completely off again with a piece of soft paper or cloth. We don't want a shortcircuit! Enough lubricant will be left to make a noticable difference.
I used this method several times, mostly for bulbs that were not unreachably high but unreachably deep inside an armature.