Practical Joke  (From Alberto Z)
 ---------------
 
 I went with my girlfriend at the time to an electronics store, we 
 were browsing through the home stereo aisle. I decided to play a 
 joke on her, so as she was looking at one stereo I moved over down 
 the row and saw one with a remote. I picked up the remote and hid 
 it to my side and called her over.  I explained to her "This stereo 
 is voice activated, just say volume up and volume down and it'll do 
 it".  She replied, "no way".
 I said "try it". So she does. She proceeds to tell the stereo in a 
 mild tone of voice, "Volume up", so I turned up the volume.  When she 
 heard the stereo turn "ITSELF" up she was totally amazed. So with a 
 huge smile she said, "volume down" and the stereo turned "ITSELF" down. 
 So I tell her, "Try it again just say it a little bit louder and the 
 stereo will go louder."  So in a louder tone of voice she says, "Volume 
 up!", so this time I decided to crank it up very, very loud. She 
 realizes it's just a little too loud so she starts yelling at the 
 stereo, "VOLUME DOWN, VOLUME DOWN!!!"  The other store patrons turned 
 and started laughing at her, especially after I showed her the magic 
 behind the volume, me! :o)