Over the weekend, President Obama's conversation with Russian President Medvedev was recorded on a live microphone that they didn't know was on. In the exchange, Obama was heard telling Medvedev that he would have "more flexibility" in terms of missile defense after the Presidential election. This frank admission of the reality and politics and foreign policy would undoubtedly never have occurred if either knew a microphone was on.
This isn't the first time that such an incident has taken place. First, check out this exchange between George W. Bush and Tony Blair at a G8 Summit in 2008, in which Bush is caught mixing foreign policy and curse words:
In the 2000 campaign, then-Governor Bush was caught telling Dick Cheney that he thought New York Times reporter Adam Clymer was "a major league a$$hole"
Ronald Reagan's off the cuff joke about "outlawing Russia forever" was captured by a live mic as well. Gotta admit, this is pretty funny, though the Soviet Union didn't think so, as they put their troops on higher alert in the immediate aftermath of Reagan's quip.
Undoubtably there are more that I missed, and we'd love to hear them! Let us know what other great moments caputred by live microphones there have been in the comments.