faster array-like slicer, aimed to replace [].slice.call(arguments). jsperf http://jsperf.com/from-slice-vs-slice-call

lodash_baseSlice.js

// https://github.com/lodash/lodash/blob/51e459b386f8301c803442f7fc722e46fc192d35/lodash.js#L2573
// 2 times faster!
function baseSlice(array, start, end) {
  var index = -1,
      length = array.length;

  start = start == null ? 0 : (+start || 0);
  if (start < 0) {
    start = -start > length ? 0 : (length + start);
  }
  end = (typeof end == 'undefined' || end > length) ? length : (+end || 0);
  if (end < 0) {
    end += length;
  }
  length = start > end ? 0 : ((end - start) >>> 0);
  start >>>= 0;

  var result = Array(length);
  while (++index < length) {
    result[index] = array[index + start];
  }
  return result;
}

slicer.js

/*
 * Author: Chris Yip <i@chrisyip.im>
 */
function slice (arrayLike, startPos, endPos) {
  if (!arrayLike) {
    return []
  }

  var result = [],
      i = typeof startPos === 'number' || startPos instanceof Number ? startPos : 0,
      endIndex = typeof endPos === 'number' || endPos instanceof Number ? endPos : arrayLike.length

  if (i < 0) {
    i = i + arrayLike.length

    if (i < 0) {
      i = 0
    }
  }

  if (endIndex < 0) {
    endIndex = endIndex + arrayLike.length

    if (endIndex < 0) {
      endIndex = 0
    }
  }

  if (endIndex > arrayLike.length) {
    endIndex = arrayLike.length
  }

  for (; i < endIndex; i++) {
    result[result.length] = arrayLike[i]
  }

  return result
}

node 0.11.14 + benchmark 1.0.0

✓  [].slice.call x 5,772,857 ops/sec ±0.94% (93 runs sampled)
✓  slicer x 13,987,134 ops/sec ±0.83% (95 runs sampled)
✓  lodash.last x 18,485,286 ops/sec ±0.95% (94 runs sampled)
Fastest is lodash.last