USB blues

Well like a lot of other folks must do, I deal with USB plugs a awful lot. I plug in my mp3 player, printers, thumb drives, etc etc etc. And one thing that endlessly bugs me is I end up putting the USB plug in upside down 50% of the time, since the top of the plug is virtually identical in appearance to the bottom, if indeed there is a top and bottom-- it will only go in one way tho, and since the 2 sides of the plug are so similar i screw it up half the time. too late to fix it now, but gee whiz, what were they thinking? not.