You’ve probably seen a police or ambulance rotating beacon. If you want to have something similar take a look at this simple project. This is a four 0603SMD LED based beacon where rotation effect is created without any moving parts.
In order to make this effect, each led has to be driven with PWM signal. Probably the trickiest part in LED beacon was to solder SMD LEDs in to shape where they look in four different sides like real beacon does.
Wattsecunde achieved this using a special holder made of four chips. He ended up with four LED bundle and five control wires (1 common cathode and 4 anodes for each LED).