This seems to be the place for the discussion on these toppers, so I figured I'd join in. A friend asked me to look into interfacing one of these... I looked at pictures online, and it looked pretty simple. Well... when I pulled his apart, I found that he had the single board surface mount version, which isn't nearly as nice to connect to. I figured I'd play around with it anyway, and after figuring out exactly how it all worked, I made a plan for interfacing to it.
So, after lifting pins and soldering wires to a microcontroller (Parallax Propeller USB Proto board), I wrote some simple code to toggle the bits manually, to verify that I knew how everything worked. That worked, so I made a framebuffer, tossed a test pattern in it, and wrote some code to output the framebuffer to the LEDs. From the picture, you can see it works (that's not just random garbage, that's my test pattern).
Now I just need to add some smarts, like a font, so it can be programmed to display messages. I'll also be adding a raw mode, to give full control of the display over the USB port.
I also dumped the TSOP flash chip and disassembled it, but didn't really spend much time trying to figure out how the protocol. I figured the cooler thing would be to have full control of the display, rather than just being able to change location name and stuff like that. I don't have a Golden Tee, so I'm not able to just sniff the RS232 lines... that's probably the easiest way to figure out the protocol if anyone's looking to just change names and stuff.