Ryan from RGB-123 kindly sent me one of his LED matrices to try out (I'd already pledged for one on his KickStarter). These are large PCBs with a grid of WS2812B LEDs on them. The LEDs are similar to the WS2811 LEDs used in the strings of lights in our rewards, but everything is completely integrated into one tiny package.
Here's a quick video showing how easy they are to use with Espruino's Graphics API:
With Espruino they'd be perfect for giant clocks or temperature displays, score boards, games, or even ambient lighting. In fact pretty much anything where you want a large, bright display...
If you want one of these, you'll have to get in quick though. Ryan's KickStarter now has less than 30 hours to go.