If you'r talking about the black Aeoniums you see in places like Santa Barbara, I saw some at Albrittons in Sarasota. You can get decent ones on eBay for like $5 so for me, it isn't worth the gas money.

Thanks, plantsman. ;>) now we have a name to research.

Aeonium arboreum cv. Schwartzkopf

Not a succulent, but if you're into black plants, this is Black Mondo Grass. It'll grow in zones 9 and 10, but needs full sun and lots of water to look this good. This cluster is from Branklyn Gardens in Scotland.