Originally Posted by Eric Montgomery
Check out Amazon or EBay and see what they've got at the moment--a search for digital kitchen scales should turn up plenty of options. I'd recommend a digital one because that will make it a lot easier to use. Also make sure it has the tare weight feature so you can zero it out with a plate or bowl on there and measure whatever you add to the plate without having to do any fancy math.
I agree with everything Eric said above. For $30 (or less) you can have a great scale. Ours still has the original batteries -- 2.5 years later...