The Gadgeteer has reviewed the Brando TEMPer Hum USB Hygrometer and Thermometer, a USB device that is supposed to tell you the temperature and humidity.
“So the conclusion to this review is that I really can’t recommend the TEMPer Hum USB Hygrometer / Temperature sensor. I know for a fact that it doesn’t measure temperature correctly, and that leads me to guess that it doesn’t measure humidity correctly either. In the mean time, I will hope that Radio Shack and analog hygrometers are accurate enough to trust. As long as I one or the other doesn’t drop below 45% for any length of time, I’ll hope that safe enough for my wooden instruments.”
Sounds like it doesn’t work very well.
(Full review at the-gadgeteer)