Black holes? On Long Island? The Relativistic Heavy Ion Collider at Brookhaven National Laboratory smashes together heavy ions (no surprise there) in an attempt to re-create the quark/gluon plasma state of the early universe. Horatiu Nastase, a bold theorist, has suggested that certain features of the resulting fireball can be understood in a “dual” description, in which the fireball becomes a ten-dimensional black hole! Duality in this sense means that there is a one-to-one map between the dynamics of the real-world fireball and the completely-imaginary black hole. This seems to be a long-shot suggestion, at best; but certainly an intriguing idea, and worth pursuing. But not in any sense an honest black hole here on Earth. (Not that we should be worried, as the little guys would presumably just evaporate away in a jiffy.)
Peter Steinberg at Quantum Diaries has a fuller explanation.
Update: in the comments, cvj (the nom de internet of Clifford Johnson) mentions that he and his collaborators have been pushing similar ideas for quite some time now. Clifford has set up a web page that talks about the phase diagrams of charged black holes in anti-de Sitter space, which could be dual to hot nuclear matter.