Why haven't these been invented?

A Velcro backed guitar with a matching Velcro shirt. This would eliminate guitar straps!

For those of us with fast growing fingernails, how about a guitar fretboard covered with emery cloth or sandpaper. Files your nails while you play!

A Harmonica-holder Hat. Instead of the acrobatics of putting on your over-the-head-around-the neck holder, just put on your hat! (Actually, my son told me that this invention exists, but I have not seen it.)

Anymore grand ideas out there?

khandu