We have had good success with the Solido Rapid Prototyping machine. I have been able to explore a number of different concepts, all at various levels of detail, that have help me understand the fit and function around the human hand. Working out the spacing and dexterity around the joints of the hand is an extremely complex exercise. RP helps to quickly reiterate concept to figure out what works.
Peeling away excess material (support structure) from laminated block from Solido machine
closeup of peeling away support material (no. 11 Xacto knife is your best friend)