diff --git a/.ipynb_checkpoints/timeit_test-checkpoint.ipynb b/.ipynb_checkpoints/timeit_test-checkpoint.ipynb
new file mode 100644
index 0000000..ed84d5c
--- /dev/null
+++ b/.ipynb_checkpoints/timeit_test-checkpoint.ipynb
@@ -0,0 +1,123 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:c78a9ef71605847c90e18bf10abda603339de473905dc928bd17aacd1ae5bee9"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "### String formatting - `.format()` vs. `%s`"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import timeit\n",
+      "\n",
+      "def test_format():\n",
+      "    return ['{}'.format(i) for i in range(1000000)]\n",
+      "\n",
+      "def test_binaryop():\n",
+      "    return ['%s' %i for i in range(1000000)]\n",
+      "\n",
+      "%timeit test_format()\n",
+      "%timeit test_binaryop()\n",
+      "\n",
+      "#print('{}: {}\\n{}: {}'.format('format()', format_res, '%s', binaryop_res))\n",
+      "\n",
+      "################################\n",
+      "# On my machine\n",
+      "################################\n",
+      "#\n",
+      "# Python 3.4.0\n",
+      "# MacOS X 10.9.2\n",
+      "# 2.5 GHz Intel Core i5\n",
+      "# 4 GB 1600 Mhz DDR3\n",
+      "#"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "1 loops, best of 3: 400 ms per loop\n",
+        "1 loops, best of 3: 241 ms per loop"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "### String Reversing - `[::-1]` vs. `''.join(reversed())`"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "def reverse_join(my_str):\n",
+      "    return ''.join(reversed(my_str))\n",
+      "    \n",
+      "def reverse_slizing(my_str):\n",
+      "    return my_str[::-1]\n",
+      "\n",
+      "\n",
+      "# Test to show that both work\n",
+      "a = reverse_join('abcd')\n",
+      "b = reverse_slizing('abcd')\n",
+      "assert(a == b and a == 'dcba')\n",
+      "\n",
+      "%timeit reverse_join('abcd')\n",
+      "%timeit reverse_slizing('abcd')\n",
+      "\n",
+      "# Python 3.4.0\n",
+      "# MacOS X 10.9.2\n",
+      "# 2.4 GHz Intel Core Duo\n",
+      "# 8 GB 1067 Mhz DDR3\n",
+      "#"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "1000000 loops, best of 3: 1.28 \u00b5s per loop\n",
+        "1000000 loops, best of 3: 337 ns per loop"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "\n"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index 6366ca7..0f93200 100755
--- a/README.md
+++ b/README.md
@@ -2,3 +2,9 @@ python_reference
 ================
 
 Syntax examples for useful Python functions, methods, and modules
+
+
+###Links to view the IPython Notebooks
+
+- [Python benchmarks via `timeit`](http://nbviewer.ipython.org/github/rasbt/python_reference/blob/master/timeit_test.ipynb?create=1)
+
diff --git a/timeit_test.ipynb b/timeit_test.ipynb
index d91402d..ed84d5c 100644
--- a/timeit_test.ipynb
+++ b/timeit_test.ipynb
@@ -1,12 +1,20 @@
 {
  "metadata": {
-  "name": ""
+  "name": "",
+  "signature": "sha256:c78a9ef71605847c90e18bf10abda603339de473905dc928bd17aacd1ae5bee9"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "### String formatting - `.format()` vs. `%s`"
+     ]
+    },
     {
      "cell_type": "code",
      "collapsed": false,
@@ -32,7 +40,7 @@
       "# MacOS X 10.9.2\n",
       "# 2.5 GHz Intel Core i5\n",
       "# 4 GB 1600 Mhz DDR3\n",
-      "#\n"
+      "#"
      ],
      "language": "python",
      "metadata": {},
@@ -55,13 +63,58 @@
      ],
      "prompt_number": 3
     },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "### String Reversing - `[::-1]` vs. `''.join(reversed())`"
+     ]
+    },
     {
      "cell_type": "code",
      "collapsed": false,
-     "input": [],
+     "input": [
+      "def reverse_join(my_str):\n",
+      "    return ''.join(reversed(my_str))\n",
+      "    \n",
+      "def reverse_slizing(my_str):\n",
+      "    return my_str[::-1]\n",
+      "\n",
+      "\n",
+      "# Test to show that both work\n",
+      "a = reverse_join('abcd')\n",
+      "b = reverse_slizing('abcd')\n",
+      "assert(a == b and a == 'dcba')\n",
+      "\n",
+      "%timeit reverse_join('abcd')\n",
+      "%timeit reverse_slizing('abcd')\n",
+      "\n",
+      "# Python 3.4.0\n",
+      "# MacOS X 10.9.2\n",
+      "# 2.4 GHz Intel Core Duo\n",
+      "# 8 GB 1067 Mhz DDR3\n",
+      "#"
+     ],
      "language": "python",
      "metadata": {},
-     "outputs": []
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "1000000 loops, best of 3: 1.28 \u00b5s per loop\n",
+        "1000000 loops, best of 3: 337 ns per loop"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "\n"
+       ]
+      }
+     ],
+     "prompt_number": 13
     }
    ],
    "metadata": {}