Jamaican food in the East Bay?
Here are a few possibilities:
Jamaica Station, 4929 Shattuck in North Oakland. Recently got a less than glowing review in the Urbanview paper, but sounded like it might be worth a try.
For sort of general Caribbean/California, try Tropix on Piedmont. The food was tasty though I doubt "real" (I'm no expert).
I've heard good things about Ma's Roti Shop on Telegraph in downtown Oakland. It's food from Trinidad, not Jamaica, but is supposed to be great and very authentic.