If you've been wondering how electronic scales work, the following may be of interest to you. Arduino enthusiast Christian Liljedahl has demonstrated how to use load cells - the device that changes electrical resistance relative to the weight upon it - with an Arduino in order to convert the measurements into useful units. Christian has made the circuitry quite simple, using a Wheatstone bridge and a simple instrumentation amplifier to measure and amplify the changes in output from the sensors.
It's a simple example, however could be used as the framework for your own measurement devices - so visit Christian's website to learn how. And for more, we're on twitter and Google+, so follow us for news and product updates as well.