According to my desk calendar, audio recording is 150 years old today.
The oldest known audio recording was made not by Thomas Edison (as was once thought), but by one Édouard-Léon Scott de Martinville, using his phonoautograph.
Unfortunately there wasn't any way to play back the audio, which was a bit of a shortcoming. But thanks to physicists at Berkeley in 2008, we can now listen to what he recorded. Awesome.
Edit: alternative link