Kill-A-Watt (P3 International, $30-$50)
Plug this electric current meter into a device and view cumulative kilowatt-hours and other information on the LCD readout. You can program the $50 version to show projected monthly costs, but it has no way of knowing peak-hour premium rates.

Watts Up (Electronic Educational Devices, $100-$240)
This line of power meters has an LCD display, but also a computer interface for data gathering. The high-end model offers Web access to the results.

PowerCost Monitor (Blue Line Innovations, $140)
A sensor fits over the power company's electric meter and wirelessly connects to a display unit. With the display unit in hand, you can watch your power consumption go up or down, in real time, as you turn hardware on or off. Note that this works only if your facility draws its power through a single, standard meter.

EML-2020 (Optimum Energy Products, $250-$300)
This portable power meter can monitor two 120-volt devices or one split-phased 240-volt device, such as an air conditioner. It includes a USB port and data gathering software, but it does not work with industrial three-phase circuits.

Kill-A-Watt PS (P3 International, $100)
This power strip and surge suppressor has a built-in current meter complete with LCD readout that lets you gauge the consumption of both a system and its peripherals.

Smart Strip Power Strips (Bits, $30-$50)
These are not meters per se, but they do gauge the flow of current, and will turn off peripherals when they detect that the computer has been turned off. This cuts off power drains from idle monitors, speakers, and printers.