I picked up a shipping scale here:
http://www.canadianweigh.com/scales/my-weigh-ultraship-seriesThey are a good source if you are in Canada, if you are in the U.S. you might find a
better deal on your side of the border.
It's sometime handy to check the weight on a package before going to the Post Office
just so you know what to expect. (Also you have a chance to figure out if you need to
repack something a different way _before_ you leave your house. ^_-)
I've also used it for weighing some of my coin dumps before taking them to the Safeway
self checkout. (It get's me within a few coins, the self check out machine will give me
an exact count, this is just so I know I don't dump so much at once that it jams the
machine. ^_-)