For background on CheerLights see: http://www.cheerlights.com/
The USB+Serial Backpack will need to be connected to a computer with Internet access via USB.
The cheerlights.pl Perl script will loop forever (well, until you kill it, or it dies) and request the file at http://api.thingspeak.com/channels/1417/field/1/last.txt which will tell it the current color. The Perl script then prints the message (in the appropriate color) to the Adafruit USB+Serial Backpack.
On the Perl side you will need the Device::SerialPort and LWP::Simple modules.
The script cheerlights_test.pl will cycle through all the colors.
The script clear.pl will clear the text from the display.
This code is released under the GPL.