[beenthere]

Any of those finger tightening gizmos or balls will work in the employment setting. To supplement those exercises and strengthen the WHOLE HAND there's a really simple exercise using a sheet of newspaper.

Take a two page sheet of newspaper by the corner, holding it with your thumb and forefinger. With the paper in front of you at arms length and using only your fingers, wad the paper up into a ball. You'll probably only be able to do one sheet every other day for a while till your hands get stronger, they'll tend to cramp if you do it too often, but thats a good place to start. Only takes a couple of minutes a night and it's easy to guage the progress with both hands.

If you want there is another exercise to strengthen forearms. Don't want to bore you unless you're interested.