Step 1: The Circuit
Here you can download the fritzing file for the circuit. Its just a simple oscillator with a 555 in astable configuration, the output square wave turns on and off two leds. The frequency is given by the capacitor between legs 1 and 2, so changing the capacitor values changes the frequency the leds turn on, experiment and choose the one you like the most. Here we try that the leds change its frequency at a high rate, so when the circuit is put to spin it sees like a continuum.
Step 2: Put It to Spin
Check the video to see what we are talking about.