FlorinC’s HDSP clock with SCD5583 display:
Here is another interesting “intelligent” LED matrix display, whose name actually makes some sense (unlike HDSP-2354, among many others): SCD5583A. I reckon it means: “Serial Character Display with 5x5x8 dot matrix”. 3 is the code is for green (0 for red, 1 for yellow).
More details on Wise time with Arduino blog.