Do you have a MacBook Air/Pro? Do you know that the cables are prone to kinks, bends, twists, breaks?http://support.apple.com/kb/HT1630
I've designed and made a clip call MagSavior - MAG clip. It can prevent your Magsafe power cable connector from fraying/damaging.
It is made from ABS (, Acrylonitrile butadiene styrene) which you could find in Lego Bricks. 3D printed in 8 vibrant colors.
Now available at http://www.magsavior.com/collections/magsavior-mag-clip