Yes, it’s happened again.  Yet another technology/trend which appeared in Neal Stephenson’s seminal novel Snow Crash has come to (almost) fruition.  I think he called it “sintergel” or some such.  This new technology joins the burbclave and a host of other trends that Stephenson predicted back in the day. 

Liquid Body Armor By End Of 2007

The company Armor Holdings is developing a liquid-type of body armor to either replace or enhance the current tough fiber and polymer armor that's in use today. The liquid can be smeared on a person, or a person's clothing, and stiffens when hit by an object. [Gizmodo]