diff --git a/system/core/Input.php b/system/core/Input.php
index e916ac6..97be9e6 100755
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -135,7 +135,7 @@
 	{
 		if ( ! isset($array[$index]))
 		{
-			return FALSE;
+			return NULL;
 		}
 
 		if ($xss_clean === TRUE)
@@ -659,7 +659,7 @@
 
 		if ( ! isset($this->headers[$index]))
 		{
-			return FALSE;
+			return NULL;
 		}
 
 		return ($xss_clean === TRUE)
diff --git a/system/core/URI.php b/system/core/URI.php
index e66cb6d..a9432e0 100755
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -358,10 +358,10 @@
 	 * This function returns the URI segment based on the number provided.
 	 *
 	 * @param	int
-	 * @param	bool
+	 * @param	mixed
 	 * @return	string
 	 */
-	public function segment($n, $no_result = FALSE)
+	public function segment($n, $no_result = NULL)
 	{
 		return isset($this->segments[$n]) ? $this->segments[$n] : $no_result;
 	}
@@ -376,10 +376,10 @@
 	 * same result as $this->segment()
 	 *
 	 * @param	int
-	 * @param	bool
+	 * @param	mixed
 	 * @return	string
 	 */
-	public function rsegment($n, $no_result = FALSE)
+	public function rsegment($n, $no_result = NULL)
 	{
 		return isset($this->rsegments[$n]) ? $this->rsegments[$n] : $no_result;
 	}
@@ -462,7 +462,7 @@
 		{
 			return (count($default) === 0)
 				? array()
-				: array_fill_keys($default, FALSE);
+				: array_fill_keys($default, NULL);
 		}
 
 		$segments = array_slice($this->$segment_array(), ($n - 1));
@@ -477,7 +477,7 @@
 			}
 			else
 			{
-				$retval[$seg] = FALSE;
+				$retval[$seg] = NULL;
 				$lastval = $seg;
 			}
 
@@ -490,7 +490,7 @@
 			{
 				if ( ! array_key_exists($val, $retval))
 				{
-					$retval[$val] = FALSE;
+					$retval[$val] = NULL;
 				}
 			}
 		}
@@ -511,7 +511,7 @@
 	public function assoc_to_uri($array)
 	{
 		$temp = array();
-		foreach ( (array) $array as $key => $val)
+		foreach ((array) $array as $key => $val)
 		{
 			$temp[] = $key;
 			$temp[] = $val;
@@ -644,7 +644,7 @@
 	 */
 	public function ruri_string()
 	{
-		return '/'.implode('/', $this->rsegment_array());
+		return implode('/', $this->rsegment_array());
 	}
 
 }
diff --git a/system/libraries/Session.php b/system/libraries/Session.php
index 783109a..4d6aa0c 100644
--- a/system/libraries/Session.php
+++ b/system/libraries/Session.php
@@ -276,7 +276,7 @@
 		$session = $this->CI->input->cookie($this->sess_cookie_name);
 
 		// No cookie?  Goodbye cruel world!...
-		if ($session === FALSE)
+		if ($session === NULL)
 		{
 			log_message('debug', 'A session cookie was not found.');
 			return FALSE;
@@ -586,7 +586,7 @@
 	 */
 	public function userdata($item)
 	{
-		return isset($this->userdata[$item]) ? $this->userdata[$item] : FALSE;
+		return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
 	}
 
 	// --------------------------------------------------------------------
@@ -715,7 +715,7 @@
 	{
 		// 'old' flashdata gets removed. Here we mark all
 		// flashdata as 'new' to preserve it from _flashdata_sweep()
-		// Note the function will return FALSE if the $key
+		// Note the function will return NULL if the $key
 		// provided cannot be found
 		$value = $this->userdata($this->flashdata_key.':old:'.$key);
 
diff --git a/tests/codeigniter/core/Input_test.php b/tests/codeigniter/core/Input_test.php
index fd0576e..a066d99 100644
--- a/tests/codeigniter/core/Input_test.php
+++ b/tests/codeigniter/core/Input_test.php
@@ -28,11 +28,13 @@
 		$this->assertTrue( ! $this->input->get());
 		$this->assertTrue( ! $this->input->get('foo'));
 
-		$this->assertTrue($this->input->get() == FALSE);
-		$this->assertTrue($this->input->get('foo') == FALSE);
+		// Test we're getting empty results
+		$this->assertTrue($this->input->get() == NULL);
+		$this->assertTrue($this->input->get('foo') == NULL);
 
-		$this->assertTrue($this->input->get() === FALSE);
-		$this->assertTrue($this->input->get('foo') === FALSE);
+		// Test new 3.0 behaviour for non existant results (used to be FALSE)
+		$this->assertTrue($this->input->get() === NULL);
+		$this->assertTrue($this->input->get('foo') === NULL);
 	}
 
 	// --------------------------------------------------------------------
@@ -68,11 +70,11 @@
 		$this->assertTrue( ! $this->input->post());
 		$this->assertTrue( ! $this->input->post('foo'));
 
-		$this->assertTrue($this->input->post() == FALSE);
-		$this->assertTrue($this->input->post('foo') == FALSE);
+		$this->assertTrue($this->input->post() == NULL);
+		$this->assertTrue($this->input->post('foo') == NULL);
 
-		$this->assertTrue($this->input->post() === FALSE);
-		$this->assertTrue($this->input->post('foo') === FALSE);
+		$this->assertTrue($this->input->post() === NULL);
+		$this->assertTrue($this->input->post('foo') === NULL);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide_src/source/libraries/input.rst b/user_guide_src/source/libraries/input.rst
index 1f2ea65..432bac3 100644
--- a/user_guide_src/source/libraries/input.rst
+++ b/user_guide_src/source/libraries/input.rst
@@ -18,7 +18,7 @@
 :doc:`controller <../general/controllers>` is invoked. It does the
 following:
 
--  If $config['allow_get_array'] is FALSE(default is TRUE), destroys
+-  If $config['allow_get_array'] is FALSE (default is TRUE), destroys
    the global GET array.
 -  Destroys all global variables in the event register_globals is
    turned on.
@@ -53,14 +53,7 @@
 having to test whether an item exists first. In other words, normally
 you might do something like this::
 
-	if ( ! isset($_POST['something']))
-	{
-	    $something = FALSE;
-	}
-	else
-	{
-	    $something = $_POST['something'];
-	}
+	$something = isset($_POST['something']) ? $_POST['something'] : NULL;
 
 With CodeIgniter's built in functions you can simply do this::
 
@@ -95,7 +88,7 @@
 To return all POST items and pass them through the XSS filter set the
 first parameter NULL while setting the second parameter to boolean;
 
-The function returns FALSE (boolean) if there are no items in the POST.
+The function returns NULL if there are no items in the POST.
 
 ::
 
@@ -115,7 +108,7 @@
 To return all GET items and pass them through the XSS filter set the
 first parameter NULL while setting the second parameter to boolean;
 
-The function returns FALSE (boolean) if there are no items in the GET.
+The function returns NULL if there are no items in the GET.
 
 ::
 
@@ -210,7 +203,7 @@
 
 	cookie('some_cookie');
 
-The function returns FALSE (boolean) if the item you are attempting to
+The function returns NULL if the item you are attempting to
 retrieve does not exist.
 
 The second optional parameter lets you run the data through the XSS
diff --git a/user_guide_src/source/libraries/uri.rst b/user_guide_src/source/libraries/uri.rst
index ee60b77..cdd76e3 100644
--- a/user_guide_src/source/libraries/uri.rst
+++ b/user_guide_src/source/libraries/uri.rst
@@ -25,7 +25,7 @@
 #. metro
 #. crime_is_up
 
-By default the function returns FALSE (boolean) if the segment does not
+By default the function returns NULL if the segment does not
 exist. There is an optional second parameter that permits you to set
 your own default value if the segment is missing. For example, this
 would tell the function to return the number zero in the event of