We came up with two LM555 astable multivibrator oscillators at two different frequencies and diode OR'ing the outputs to an blue LED, these two frequencies would beat together and cause the flickering effect you see on the video below. The student designed the circuit in GEDA and made a PCB using Protel to the T-Tech 5000 PCB Milling Machine.
This proved our rapid design process, the whole circuit form conception to working product was done in under 6 hours.
PCB one of a kind proto type
Candle in action