Invece di creare infinite funzioni con bind (in generale non è mai una buona idea abusare di bind) creane una sola e falle sfruttare i diversi id degli elementi in questione. Altrimenti un'altra possibilità è usare l'attributo class, come in questo esempio:

codice:
<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Draggable objects</title>
<script type="text/javascript">

var bMouseUp = true, oDragging, nMouseX, nMouseY, nStartX, nStartY, nZFocus = 100 /* the highest z-Index present in your page plus 1 */;

function dragDown(oPssEvt1) {
  var bExit = true, oMsEvent1 = oPssEvt1 || /* IE */ window.event;
  for (var iNode = oMsEvent1.target; iNode; iNode = iNode.parentNode) {
    if (iNode.className === "draggable") { bExit = false; oDragging = iNode; break; }
  }
  if (bExit) { return; }
  bMouseUp = false;
  nStartX = nStartY = 0;
  for (var iOffPar = oDragging; iOffPar; iOffPar = iOffPar.offsetParent) {
    nStartX += iOffPar.offsetLeft;
    nStartY += iOffPar.offsetTop;
  }
  nMouseX = oMsEvent1.clientX;
  nMouseY = oMsEvent1.clientY;
  oDragging.style.zIndex = nZFocus++;
  return false;
}

function dragMove(oPssEvt2) {
  if (bMouseUp) { return; }
  var oMsEvent2 = oPssEvt2 || /* IE */ window.event;
  oDragging.style.left = String(nStartX + oMsEvent2.clientX - nMouseX) + "px";
  oDragging.style.top = String(nStartY + oMsEvent2.clientY - nMouseY) + "px";
}

function dragUp() { bMouseUp = true; }

document.onmousedown = dragDown;
document.onmousemove = dragMove;
document.onmouseup = dragUp;

</script>
<style type="text/css">
.draggable {
  position: fixed;
  left: 0;
  top: 0;
  width: auto;
  height: auto;
  cursor: move;
}

#myDiv {
  width: 300px;
  height: 200px;
  left: 200px;
  top: 200px;
  background-color: #00ff00;
}
</style>
</head>

<body>

<div class="draggable" id="myDiv">

Hello world!</p></div>
<div class="draggable" style="background-color:#aaaaaa;">Another hello world!</div>

</body>
</html>
https://developer.mozilla.org/en/DOM...nt.onmousemove