A recent post on the "Wired Campus" blog of the Chronicle of Higher Education describes efforts by the editors of the Oxford English Dictionary to strengthen the dictionary's collection of words created by soldiers who fought in World War I. The OED is using crowdsourcing (a word coined in 2005) to find, for example, early references to the phrase "Zeppelins in a cloud" (as a substitute for bangers and mash or, to the unBritish, sausages with mashed potatoes).
As the article notes, wars tend to produce a lot of neologisms. Some originate in soldiers' mangling--or playful distortion--of foreign words and phrases they pick up while fighting in a different country or alongside troops speaking a different language. In World War I, British soldiers took the French phrase "jusqu' au bout" ("to the end") and turned it into "jusqu'auboutiste" ("someone who fights to the bitter end"). "Napoo," a synonym for "dead," seems to have come from the French phrase "il n'ya plus," which means "he is no more."
The OED Appeals web page is located here, for those who want to be part of the crowd helping the editors source these and other World War I words.