Got this little gem: http://shop.ciseco.co.uk/pi-lite-lots-of-leds-for-the-raspberry-pi-0805-red/
And this python script to make it talk:
#!/usr/bin/env python
# Pi-Lite init part...
import serial
from time import sleep
baud = 9600
port = '/dev/ttyAMA0'
ser = serial.Serial(port, baud)
ser.timeout = 0
ser.flushInput()
# And from here, the actual programming !
import sys
ser.write(sys.argv[1])
Use it like this:
python write.py "Hello, my name is Dick"