this is the archimedes scale, by federica castagno and sara petrucci. such a simple design, this is just the kind of thing i need. it doesn't take up much space, it can be used as a bowl as well as scales, and i can't see why it wouldn't function great too! using the principle of buoyancy in the water, the bowl indicates what weight is inside it by how much it sinks. the only downside i can possibly imagine is having to fill up your sink or an even larger bowl with water.