_.js

var makePile = function(count, onfilter, onvalue) {
  var values = []
  var id = function(value) {
    // console.info('onvalue::', value)
    return value
  }
  return function(value) {
    values.push((onvalue || id).apply(this, arguments))
    if (values.length === count) {
      onfilter.apply(this, values)
      values = []
    }
  }
}

application.js

var f = makePile(2, function(a, b) {
  console.info('f onfilter::', arguments)
})
 
var g = makePile(3, function(a, b, c) {
  console.info('g onfilter::', arguments)
})
 
var i = 0
while (i++ < 10) {
  f(i)
  g(i)
}
 
/* =>
f onfilter:: [1, 2]
g onfilter:: [1, 2, 3]
f onfilter:: [3, 4]
f onfilter:: [5, 6]
g onfilter:: [4, 5, 6]
f onfilter:: [7, 8]
g onfilter:: [7, 8, 9]
f onfilter:: [9, 10]
*/

application_2_ajax.js

var request = makePile(5, function() {
    $.post('/api', { list: JSON.stringify([].slice.call(arguments)) })
})

request({a:1})
request({a:2})
request({a:3})
request({a:4})
request({a:5})
/*
list:[{"a":1},{"a":2},{"a":3},{"a":4},{"a":5}]
 */

pile_debounce.js

var touchFactory = function(delay, action) {
  var params = [], slice = [].slice
  var touch = debounce(delay, function() {
    if (params.length) {
      action(params)
      params = []
    }
  }, true)
  return function() {
    params.push(slice.call(arguments))
    touch()
  }
}

//
touchItem = touchFactory(550, function(params) {
    $.post('/touch', { 'items': JSON.stringify(params) })
})