The most minimal draggable

gistfile1.txt

var draggable

// disable IE specialities
document.ondragstart = function () { return false }

// bound dragging into document
var doc = $(document).bind("mousedown mouseup", function(e) { 

  var el = $(e.target)

  if (e.type == "mousedown" && el.data("drag")) { 
    var y = el.offset().top - e.pageY
    
    doc.bind("mousemove", function(evt) {
      if (!draggable) {
        draggable = el.css({position: 'absolute'})
        el.trigger("dragstart")
      }
      el.css({ top: evt.pageY + y }).trigger("drag")
    }) 

    e.preventDefault()

  // mouseup
  } else if (draggable) {
    draggable.css({ position: 'static'}).trigger("dragend")
    doc.unbind("mousemove")
    draggable = 0
  }

})

$.fn.mootdrag = function() {
  return this.data("drag", true)
}