Electrical engineers, hardware engineers and telecom technicians are just a few of the professionals who use these instruments to measure
different attributes of electricity, such as voltage, resistance, current and frequency. Any geek who likes to tinker will have a multimeter. In this
photo, Stephen Holiday used a multimeter (the black object with the digital screen near the upper left corner of the photo) while making a
portable battery pack for an MP3 player and a wall charger.
Slideshow: Evolution of the MP3 Player