We have seen a bunch of awesome LEGO creations in the past. Time Twister by Hans Andersson is quite impressive though. It consists of two LEGO Mindstorms bricks that communicate via Bluetooth. The main brick keeps track of the time and controls the minute digits while the slave brick takes care of hours and seconds.
Each layer is made up of five layers with black and white tiles and can rotate 360 degrees. The above video shows how this LEGO clock works.