Well this is a fine kettle of fish: Apple has added a secret folder to our file systems that essentially sucks any content inside into iTunes. The watched folders are:

~/Music/iTunes/iTunes Music/Automatically Add to iTunes/ in OS X

C:\Users\Your Username\Music\iTunes\iTunes Media\Automatically Add to iTunes\ in Windows

If you drop an MP3 into there they get sucked into iTunes and disappear immediately, like a magic box. This would allow you to record your own music, for example, and add it to iTunes when you mix down and/or drag all your recently downloaded tunes straight into iTunes.

Apple didn’t quite publicize this feature for obvious reasons. Maybe this is the folder where they stuck the part of the presentation on the iPod touch with camera?

via LifeHacker