Coming to you soon from the research labs of Baltimore Gas and Electric Co.: The annoyingly smart thermostat, also called the Nag-o-Meter.

When this new device is installed in your home, the moment you attempt to switch on your air conditioning at a peak hour you'll hear a familiar voice (it can be programmed to sound like your boss, your least treasured relative or a TV talking head you particularly dislike):

"Whoa! Do you know what a kilowatt hour costs right now, chump? Are you rich? You don't look it. Just how cool do you need to be anyway? Why don't you get some ice water instead? But be careful not to open the...