The only one I know of is Kelley's Caribbean in Key West. I don't want to speculate on how good it is as I've only had one of their brews (not a big drinker). I thought that that one was good though. You'll find it on the corner of Whitehead and Caroline.
Just Saw this thread. There's some great shops down here now. "The Krawl" just off Duval on Southard St. "The Porch" on Duval and Caroline. Key West Home Brew just off Duval on Appelrouth Lane.