Got my Arduino LCD message scroller working last night, will post a video later when I do an end to end test with my Twitter mentions.

Here is the code (also at GitHub https://github.com/alastairhm/arduino.git)

// Auto scroll a message on the LCD and receive new messages via Serial port.
// Alastair Montgomery (c) 2013
// Version 1.02
 
// include the library code:
#include <LiquidCrystal.h>
#include <string.h>
// initialize the library with the numbers of the interface pins
// below for SainSmart LCD Shield
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);