Posting a fun project I recently built that folks here might appreciate. The load cell from a cheap kitchen scale is amplified and sent to an Arduino which communicates to an Android application (through bluetooth or USB). By measuring the weight of ingredients and using the density of liquids, the application can show in real time exactly how much has been added to the shaker. Making a drink is as easy as following the steps on the app--no messing around with measuring stuff by hand.