From www.straightdope.com The correct term is, "hear, hear!" It is an abbreviation for "hear, all ye good people, hear what this brilliant and eloquent speaker has to say!"
Of course, if the speaker is actually asking a question. "and just where do you think we should open the new strip club?" it's not hard to imagine that at least one yahoo in attendance might yell, "here, here!" But this would be the exception that proves the rule.
Usually used by pseudointellectuals who have nothing better to say and are merely trying to sound grand and majestic.
People who seriously said "hear hear" are dead since three hundred years. The ones using it today fancy themselves classy and clever, but only come off as arrogant, pretentious, and shallow.