digitalmisery created this neat “jacob’s ladder” using EL wire and a WaveShield:

Created using LyTec electroluminescent (EL) wire, driven by a
IFW 3294 inverter (Coolight.com), with the Sparkfun.com EL Sequencer, an Arduino USB Board (arduino.cc), a WaveShield (adafruit.com) and a PIR Sensor.

A new take on an old favorite.