If you have an old pair of headphones that don't work any longer, cut off the end.
You can also find headphones at your local Dollar Store.
Don't worry about gettin' zapped 'cause the jack will still be encased with rubber when you cut it.
Use charms, buttons or anything you'd like to decorate your jack. I bought mine at Michaels.
Use a strong clear adhesive and glue it to the jack.
This one's for my daughter.
Cuteful? I vote yup!