"It’s like if you or I morphed into fully functioning cyborgs after being thrown into a room of electronic scrap with nothing to eat."

The newly discovered arsenic-eating bacteria. But it's not really that weird:

Arsenic sits right beneath phosphorus in the periodic table of the elements and shares many of its chemical properties. Indeed, that chemical closeness is what makes it toxic, Dr. Wolfe-Simon said, allowing it to slip easily into a cell’s machinery where it then gums things up, like bad oil in a car engine.

At a conference at Arizona State about alien life in 2006, however, Dr. [Felisa] Wolfe-Simon suggested that an organism that could cope with arsenic might actually have incorporated arsenic instead of phosphorus into its lifestyle. In a subsequent paper in The International Journal of Astrobiology, she and Ariel Anbar and Paul Davies, both of Arizona State University, predicted the existence of arsenic-loving life forms....

Reasoning that such organisms were more likely to be found in environments already rich in arsenic, Dr. Wolfe-Simon and her colleagues scooped up a test tube full of mud from Mono Lake, which is salty, alkaline and already heavy in arsenic, and gradually fed them more and more.