According to the Oxford English Dictionary, we've been saying OMG for a lot longer than we think. In fact, some of the buzzwords / phrases we think are new, are kind of old.

OMG - an abbreviation for Oh My God, first appeared in a letter written to Winston Churchill in 1917. The word "unfriend", thought to be associated with social networks, actually dates back to 1594. Possible example: Unfriend your neighbor because he makes love to goats?