Star Trek fans, remember the Bird of Prey? That was the Romulan warship that confounded the unflappable James T. Kirk when it materialized right under his nose and began to blast away. (This was the 1960s cool James T. Kirk, not the 90s cool James T. Kirk.)
Anyway, the idea of cloaking — making an object invisible to keep it safe — has been around for a while, usually in the wide spaces of science fiction. But it seems that more than one team of researchers have come up with practical ways to apply, and implement, cloaking tech.