Besides just turning ON and OFF, there are lot of other stuff that you can do with LEDs. In one of my experiments, I showed how to control the intensity of an LED using PWM. Here's a project that uses the similar concept to generate 8-channel PWM signals through PIC16F628A ports and drive 8 LEDs with 4 levels of intensity. A number of visual effects and chase sequences are programmed into the firmware. Enjoy watching this video!