Here's a demo on how to make an LED board in GE.
It starts with a clonearray of the led's, with on and off animpos.
Make sure to parent them to another actor before you clone them, or it could get messy!
The only trick is to make sure your images have lots of space in them.....or else the led's won't turn off correctly.
For text, this means that ARIAL normal is the best font to use.
It also means that the smaller and more numerous your led's are, the clearer the images will be. (duh).
Use the mouse to move the letters, right click the letters to make them flash on and off.