We like gadgets, particularly versatile ones that offer redundancy for other on-board systems. The Skywatch Windmate, made by JDC Electronic SA comes in four models and senses not only windspeed, but the ambient temperature, the windchill factor, wind direction, the altitude, and the relative or absolute pressure. (Only one model does all of the above.)
We tried out the Windmate on a breezy day and got instant windspeed readings that jibed with those from our Plastimo Electronic Wind Gauge. The ambient temperature agreed with readings from an in house thermometer, but we had difficulty calibrating the compass, and thus couldn't test that function. We also didn't check the windchill, altitude, or relative or absolute pressures.
At $150, this Lilliputian gem (1 1/2 x 3 x 3/4 inches; weight 53 grams) isn't cheap, but would be a good back-up to built-in anemometers. However, it's a sensitive instrument and deserves a protective case, which isn't offered. Changing batteries is a delicate process, but the unit is rated for 25,000 1-minute readings, and comes with back lighting and an automatic shut-off.
Contact - Speedtech Instruments, 800/760-0004, www.speedtech.com.