*sort of* like getBoundingClientRect() but it takes transforms into account.

gistfile1.txt

function getRenderedRectangle(element, root) {
  if (!root) root = document;
  var width = element.offsetWidth,
      height = element.offsetHeight,
      topLeft = webkitConvertPointFromPageToNode(root, webkitConvertPointFromNodeToPage(element, new WebKitPoint(0, 0))),
      topRight = webkitConvertPointFromPageToNode(root, webkitConvertPointFromNodeToPage(element, new WebKitPoint(width, 0))),
      bottomLeft = webkitConvertPointFromPageToNode(root, webkitConvertPointFromNodeToPage(element, new WebKitPoint(0, height))),
      bottomRight = webkitConvertPointFromPageToNode(root, webkitConvertPointFromNodeToPage(element, new WebKitPoint(width, height)));

  return [topLeft, topRight, bottomRight, bottomLeft];
}