Mobile phones have a lot to answer for! Yes we'd all be lost without them, and ok we've almost come to terms with annoying ringtones; but, why do they insist on having speakers?! You can't get on a bus or a train now without seeing a group of kids all huddled around some ones phone, listening to music that can only be described as 'tinny' at best!
The hi-jack allows you to plug two sets of earphones into one phone or MP3 player so that two people can listen to the same music, without bothering anyone else! Now that's music to our ears!