Round Guitar Pick
This pick allows for many choices of edges to choose from while playing. The 3D printer may make the surface less smooth than those cheap picks out there, but the 3D printed one is easy to hold.
The rounded pick also has a hole in the center to allow for storage in a rope or chain.
I have given this to a few players to try and so far they love it.
You can get customizable color nylon versions on Shapeways.