SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<div id="elm0" data-color="color" data-size="size" data-more="more">something</div>
<div id="elm1">This element must get elem0 attr</div>

JavaScript

jQuery.fn.copyDataAttrTo = function(selector) {
    var a = this[0].attributes, attrMap = {};
  for(var i=0; i<a.length; i++) {
     if(a[i].name.indexOf("data-") == 0) attrMap[a[i].name] = a[i].value;
  }
  $(selector).attr(attrMap);
  return this;
};
$("#elm0").copyDataAttrTo("#elm1");
alert($("#elm1").attr("data-more"));