I altered the jQuery plugin posted above so it would work on live elements.
(function ($) {
$.fn.disableSelection = function () {
return this.each(function () {
if (typeof this.onselectstart != 'undefined') {
this.onselectstart = function() { return false; };
} else if (typeof this.style.MozUserSelect != 'undefined') {
this.style.MozUserSelect = 'none';
} else {
this.onmousedown = function() { return false; };
}
});
};
})(jQuery);
Then you could so something like:
$(document).ready(function() {
$('label').disableSelection();
// Or to make everything unselectable
$('*').disableSelection();
});