I designed an LM317 power supply PCB as part of an introduction to PCBs workshop that I conducted in the UQ Robotics Club. The PCB circuit is taken straight from Figure 9 of the data sheet (see LM317_datasheet). The point of this exercise was PCB design and so I developed a guide on how to design PCBs using Eagle. You can view the guide here: guide.
This PCB was used to teach other students how to make custom components, layout schematics and route PCBs. The Eagle design files that were made live on the night of the workshop can be found downloaded here: eagle_files.
The finished PCB can be used as the core part of a benchtop power supply (if the potentiometer is switched out for one with a larger knob). I have personally used the breakout board for heaps of different things such as hacking an RC car from Kmart, making a remote control from scratch, and testing various circuits when my lab power supply is busy powering other things.
And here’s the regulator PCB: