Save money on your electric bill by knowing where your electricity drains are. I purchased this great little device from Amazon. It is very straightforward: plug in the P4400 Kill A Watt monitor and plug in your electrical device for an instant reading of electricity usage. I made a simple spreadsheet that lets me input the usage, average hours used per day, and the cost of electricity. It calculates the total cost of electricity used each month by appliance. I discovered that our cable box DVR was sucking as much power as our television was, but it was doing this 24 hours per day. The Kill A Watt also showed the savings we expect by changing many of our light bulbs to more energy efficient models. I have loaned the device to a few friends for them to check their own homes. The P4400 Kill A Watt has paid for itself in less than one month with our savings.