Here is a rigged hand I made in Blender some time ago.
Some projects where this hand has found a use:
-Chloe Adeline used this hand for his webside fingerspell http://fingerspell.net/#/spell
-Blender Game Engine - Crysis-like Weapon attachment System by Lars Pfeffer
-First person basics by Rocco martino
-The Island - [Open World Survival Game] (BGE) New Features by Blenderrendersky
Blendfile download: http://www.blendswap.com/blends/view/66039
Each finger can be controlled with only one control bone per finger also there is a separate control bone for making a fist by using an action constraint which controls all fingers and the thumb (in Blender).