Update from last week:

Went to Digicell at Mega Mart in MoBay and was told that they do not accept American or Foreign ID's anymore.
She told me she could only sell sim cards to Jamaicans...
I had a hunch she was lying as I was already cut in line twice with her waiving those behind me to the counter...
So I went to the customer service desk and they said "what?" and they said they would look into it...

Maybe she was just having a bad day but I will never go back to MegaMart as the prices were not any better than the HiLo in Negril...

Just be aware, she said the "new" Digicell system does not take foreign ID's.
May not be a fact, just my first hand experience...

Got a loaner sim from a local driver to use with my JA cell and bought some minutes at the HiLo and was good to go...