SamCo got a MakerBot Industries Thing-O-Matic 3D printer. It prints in ABS plastic (the same stuff LEGOs are made of).
It prints parts layer by layer.
I even used my 3D printer to print out some spool holders for my 3d printer! I love using a machine to make parts for that same machine.
The plastic comes on spools. Because the printer can only print in a 4" cube, this spoolholder design prints in two parts. The bottom part has a bracket that clips on the top of the Thing-O-Matic and has a dovetail on the top. The holder portion then mates with that dovetail. You print out two of the bottom pieces, two of the top pieces, and then use them to hold your spool. You can see it assembled in the first picture.
I found this bracket on thingiverse.com, where people upload their 3D designs. You just find something you like, download it, and then print it out!
