I bought an $8 "luggage" scale on eBay, too. Supposedly accurate to .1 oz. Is it? Dunno. Probably. It seems to catch fine distinctions when I'm weighing some light stuff and then add a little more light stuff.

The important thing to remember is when you're weighing your fully built bike, always subtract 2 - 3 lbs when you post the weight here in the forums, so we'll all be impressed with your mad weight-weenie bike building skilzz.