This is a set of 4 fingers for a Lego Technic gripper as used in the Mindstorms NXT 1.0 set (8527)
Unfortunately the new NXT 2.0 set (8547) contains different components and the gripper parts are no longer in the box.
The design mimics the original Lego design but is different on some details.
Update on 2-Feb-11: The edges looked a bit rough due to the layering so I added a fillet to make the edges more smooth. Also made the mounting holes for axle and pegs a bit wider to have an easier fit on standard Lego components.
Note that these 4 fingers are stacked together on small (1.5 mm) pegs. You need to cut them apart and file off the excess material left. If you are not comfortable doing so, you should order 4 separate fingers
but note that these are more expensive since Shapeways handles them as 4 separate objects (each with its own startup cost).
Please note: I am still waiting for the first 3D prints so I am not sure about the fit.LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this site.