Ben Krasnow wanted to use a cheap digital scale to use in a project that needs to automatically dispense the correct amount of material and stop when the appropriate weight has been achieved. We have seen this type of system used in factories that bag things by weight such as potato chips. These small scales use a strain gauge to read how much weight is on the scale. The strain gauge is fed into a 24 bit analog to digital converter which is read in by a microcontroller and the microcontroller simply sends the appropriate data to the LCD driver to show the user what is going on. The data coming out of the A to D chip is clocked very fast so a normal microcontroller like an ATMega used in an Arduino would not cut it. Ben used a Parallax propeller to handle the speed since the propeller chip has many cores, one of these cores was dedicated to reading in the high speed data.
If you are curious what Ben is building you can see his Cookie machine project here.