Greeeg over at the 430h forum has been working on a RGB LED ring clock:
The clock is comprised of 2 rings of 60 LEDs each. the LEDs are WS2812 parts, which include a built-in driver.
The PCB is one of the interesting parts of this clock. I designed the board in altium as a single 6 LED segment. and then left pads at each end to allow them to be soldered onto another segment.
Currently I am using a MSP-EXP430FR5739 board to drive it, using some very in-efficient assembly code that requires a 20MHz clock.