I have a very accurate scale I am very happy with - it wasn't cheap but it is good. It will do either ounces or grams and can be "zeroed" repeatedly. It has a toggle switch that controls whether it shuts itself off after 5 sec or stays on until you toggle it again. It has a flat and a bowl top which you can switch.
It is "Ohaus Lume-O-Gram" Balance by Ohaus Scale Corporation, 29 Hanover Road, Florham Park, NJ 07932.
DH picked it up for me, probably from one of his test equipment catalogs (we have GEEK written all over us

).