The word "Blarney" originated with Queen Elizabeth I of England.  The queen had commissioned the Earl of Leicester to obtain the rights to Blarney Castle from a man named McCarthy.  Whenever, the earl broached the subject, McCarthy would suggest a party or banquet to delay settling the matter.  After many "progress reports" from the earl, the queen demanded the end to the "Blarney" and wanted action.

For example, it would be completely wrong to walk up to the pig on the left and say, "Pig, you are beautiful," no matter how much she painted her body.  If the speaker were anything other than a pig, that would clearly be a lie.  It would, however, be perfectly acceptable, according to the rules of blarney, to say to a pig, "You, pig, are the most enchanting creature I have seen today," assuming you hadn't seen any other creatures that day.

Perhaps one of the best examples of blarney the we have heard came after a dinner where the roast was burned completely beyond recognition.  At the end of the meal, the hostess asked how everyone enjoyed their meal.  In response to the question, one guest raised her glass and politely stated, "I lift my glass to our friends and the most unique meal I have ever sat down to!"  You will note that the speaker didn't lie at all.  Rather, she turned a difficult moment into flattery as smoothly as possible considering the situation.

Even presidents have discovered the benefits of blarney.  Once Abraham Lincoln was asked what he thought about a book by its author.  The fact was that he didn't like the book at all.  Rather than offend the the person, Lincoln said, "If you like that kind of thing, it is very good."