Here's a robot video that I found interesting:
Using 3D printing to design and manufacture a quad head for the siphon used in the Japan Aquaponics Micro system. The design goal was to increase aeration of the water exiting the siphon and create more of a current in the fish tank, while avoiding any restriction of the water flow. The design process took about 30 minutes plus another 35 minutes to print the part on a Tantillus RepRap 3D printer. The quad head was printed in PLA, since PLA is food safe and won't leach chemicals into the system. Print layer height was 100 microns.