I discovered some inexpensive LED matrix panels on eBay from Sure Electronics -- there are threads elsewhere in the forums on these. Since they have a nice serial protocol to control them, they were perfect to do some wall signs.
Haven't designed an enclosure for this one yet, but it pulls entries from my twitter feed and shows the person's picture on the OLED and then scrolls the tweet text in the LED display:
This one combines a few sizes of the LED matrix parts into a laser-cut acrylic enclosure. Driving the LEDs is really simple and the parts are cost-effective.
The OLED panel is from Sparkfun. It's cool but you talk to it through a fairly slow serial link so it takes a long time to push the images to it. Fortunately you can add a microSD card to it and cache the images there so subsequent displays are quick.
I've used the 32x8 ones as well. They have the same driver chip and you can daisy chain both sizes and control up to 4 of them with just 3 arduino output pins.
