How do I know what kind of electricity monitor is right for my house? The simplest electricity monitor on the market now is the Kill-a-Watt. It plugs directly into an outlet and immediately presents basic information about a device's electricity usage. The Watts Up? monitors are more sophisticated. The standard Watts Up? model measures voltage and current thousands of times a second, for any 100-250 VAC device plugged into it, and displays the results on an LCD screen. The basic Pro version includes software and a USB connection that allows you to download usage data onto a computer. The Pro ES has greater data storage capacity, and can hold over 120,000 records in memory. Finally, the RT software, an enhancement for the two Watts Up? Pro models, allows "real time" viewing and graphing of usage data along with automated email notifications.