Strait-Line Sonic Laser Tape

This here is a fascinating little gadget. It measures distances between 1.5 feet and 50 feet using a "sonar" method. Press the "Read" button, and it'll emit a short click, measuring the distance and displaying it on the LCD. It can use multiple length units, measures length, area, or volume, and is a darn sight handier than a regular tape measure, especially if you're by yourself. Just set the base at one end of whatever you want to measure, and press the "Read" button. It includes the length of the unit in its measurements. A laser is automatically activated to help you aim.

This unit operates at 8.1V, using 0.2mA (1.62mW) when simply displaying the last measurement, and using 14.6mA (118.26mA) when making a measurement. Long, long battery life.

Below is the sonic emitter (sounds cool, doesn't it?).

There's a slide-out belt clip built in.

There are some drawbacks to this device: the target surface must be reasonably smooth to reflect the sound back, and it must also be nearly perpendicular to the unit, also to reflect the sound back. At $30-40, it's more expensive than an analog tool, but it's cooler.