<br>If all you wanted to do was tell the temperature cheaply, then sure, of course that would be fine. A small sundial could also be used for time, and I supposed you could find a cheap hygrometer(?) for barometric pressure. A golf pencil, and a piece of paper and you could chart it all over time too, and heck, maybe even figure out your altitude. A magetized needle in your pocket could be used as a compass. A small photon light and you can even view it at night, except for the sundial of course.<br><br>For everything there's always a cheaper, or more accurate, or more reliable, or smaller, etc, solution. That's why there are a million products for sale. Different strokes for different folks.<br>