They say you cannot make a design with conductive traces out of mirror acrylic because "the mirror surface is not conductive." Made it anyway; here is the result.
The circuit board is the same 3 mm mirror acrylic from Ponoko. The design is based on a simple blinker originally designed to test KiCAD and OSH Park. The PCB design was exported to SVG format, adapted for Ponoko specifications, and scaled up two times to make it easier to connect the components and wires to the mirror coated surface with the so-called "wire glue." It turns out, the mirror coating really is conductive, but can be accessed only along cuts and vector engravings. It also turns out, wire glue fails at actually gluing wires. I had to add a little bit of clear tape to the back to make them hold in place.
The circuit is an astable multivibrator:
The only difference are the LEDs in series with the collectors and the resistors (680 Ohm) associated with them.
The electronic components this blinker uses are:
2x white LEDs
2x 2N2222 NPN transistors
2x 1 uF capacitors
2x 680 Ohm resistors
2x 1 M resistors
A word of advise if anyone plans to do something similar: make the solder pads bigger. Wire glue is difficult to work with compared to solder, and it is easy to have a tiny drop cause a short over a vector-engraved line. I had to clean it up with an Exacto knife.