betterScrollEvent

combined.js

var root = DOM(window)
  , isScrolling = false
  , interval

    function getScrollState() { // verifies if window is still scrolling
      if(!isScrolling) isScrolling = true
    }

    function getScrollStart() { // targets scrollStart and stops immediately
      root.stopListening("scroll", getScrollStart).listen("scroll", getScrollState)
  
      interval = (function () {
        if(!isScrolling) { // if scroll is stopped, target start again and stop listening at scrollState
          root.stopListening("scroll", getScrollState).listen("scroll", getScrollStart)
          window.clearInterval(interval) // stops interval
          return
        } else {
          isScrolling = false
          // callback
        }
      }).every(.03) // slows down scrollEvent firing speed
    }

root.listen("scroll", getScrollStart)

interval.js

var root = DOM(window)
  , isScrollingMethod2 = false


root.listen("scroll", function(){
  isScrollingMethod2 = true
})
		
;(function(){
  if(isScrollingMethod2) // callback 
  isScrollingMethod2 = false
}).every(.03)

scrollEvent.js

DOM(window).listen("scroll", function(){
  // callback 
})

This little script slows down the firing speed on scroll event, and if no scroll is detected, the setInterval that handles restraint firing is stopped.