jQuery UI Resizable - Visual feedback
#resizable { width: 150px; height: 150px; padding: 0.5em; }
#resizable h3 { text-align: center; margin: 0; }
.ui-resizable-ghost { border: 1px dotted gray; }
$(function() {
$("#resizable").resizable({
ghost: true
});
});
Ghost
Instead of showing the actual element during resize, set the ghost option to true to show a semi-transparent part of the element.