diff --git a/README.md b/README.md
index 8d9a4b1..9fab776 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,7 @@ if($v->validate()) {
  * `dateFormat` - Field is a valid date in the given format
  * `dateBefore` - Field is a valid date and is before the given date
  * `dateAfter` - Field is a valid date and is after the given date
+ * `contains` - Field is a string and contains the given string
 
 ## Adding Custom Validation Rules
 
diff --git a/composer.json b/composer.json
index 7990087..3fba12d 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
     "name": "vlucas/valitron",
-    "version": "1.0.1",
+    "version": "1.0.2",
     "type": "library",
     "description": "Simple, elegant, stand-alone validation library with NO dependencies",
     "keywords": ["validation", "validator", "valid"],
diff --git a/lang/en.php b/lang/en.php
index ac657cc..755761a 100644
--- a/lang/en.php
+++ b/lang/en.php
@@ -22,6 +22,7 @@ return array(
     'date' => "Invalid date",
     'dateFormat' => "Must be date with format '%s'",
     'dateBefore' => "Must be date before '%s'",
-    'dateAfter' => "Must be date after '%s'"
+    'dateAfter' => "Must be date after '%s'",
+    'contains' => "Must contain %s"
 );
 
diff --git a/src/Valitron/Validator.php b/src/Valitron/Validator.php
index 3282e4f..c90fe5a 100644
--- a/src/Valitron/Validator.php
+++ b/src/Valitron/Validator.php
@@ -23,6 +23,7 @@ class Validator
 
     const ERROR_DEFAULT = 'Invalid';
 
+    protected $validUrlPrefixes = array('http://', 'https://', 'ftp://');
 
     /**
      *  Setup validation
@@ -241,6 +242,25 @@ class Validator
         return !$this->validateIn($field, $value, $params);
     }
 
+    /**
+     * Validate a field contains a given string
+     *
+     * @param  string $field
+     * @param  mixed  $value
+     * @param  array  $params
+     * @return bool
+     */
+    protected function validateContains($field, $value, $params)
+    {
+        if(!isset($params[0])) {
+            return false;
+        }
+        if (!is_string($params[0]) || !is_string($value)) {
+            return false;
+        }
+        return (strpos($value, $params[0]) !== false);
+    }
+
     /**
      * Validate that a field is a valid IP address
      *
@@ -274,7 +294,12 @@ class Validator
      */
     protected function validateUrl($field, $value)
     {
-        return filter_var($value, FILTER_VALIDATE_URL) !== false;
+        foreach ($this->validUrlPrefixes as $prefix) {
+            if(strpos($value, $prefix) !== false) {
+                return filter_var($value, FILTER_VALIDATE_URL) !== false;
+            }
+        }
+        return false;
     }
 
     /**
@@ -286,9 +311,14 @@ class Validator
      */
     protected function validateUrlActive($field, $value)
     {
-        $url = str_replace(array('http://', 'https://', 'ftp://'), '', strtolower($value));
+        foreach ($this->validUrlPrefixes as $prefix) {
+            if(strpos($value, $prefix) !== false) {
+                $url = str_replace($prefix, '', strtolower($value));
 
-        return checkdnsrr($url);
+                return checkdnsrr($url);
+            }
+        }
+        return false;
     }
 
     /**
@@ -420,7 +450,18 @@ class Validator
      */
     public function error($field, $msg, array $params = array())
     {
-        $this->_errors[$field][] = vsprintf($msg, $params);
+        $values = array();
+        // Printed values need to be in string format
+        foreach($params as $param) {
+            if(is_array($param)) {
+                $param = "['" . implode("', '", $param) . "']";
+            }
+            if($param instanceof \DateTime) {
+                $param = $param->format('Y-m-d');
+            }
+            $values[] = $param;
+        }
+        $this->_errors[$field][] = vsprintf($msg, $values);
     }
 
     /**
diff --git a/tests/Valitron/Validate.php b/tests/Valitron/Validate.php
index d70a573..be59089 100644
--- a/tests/Valitron/Validate.php
+++ b/tests/Valitron/Validate.php
@@ -396,5 +396,26 @@ class ValidateTest extends \PHPUnit_Framework_TestCase
         $v->rule('dateAfter', 'date', '2013-01-28');
         $this->assertFalse($v->validate());
     }
+
+    public function testContainsValid()
+    {
+        $v = new Validator(array('test_string' => 'this is a test'));
+        $v->rule('contains', 'test_string', 'a test');
+        $this->assertTrue($v->validate());
+    }
+
+    public function testContainsNotFound()
+    {
+        $v = new Validator(array('test_string' => 'this is a test'));
+        $v->rule('contains', 'test_string', 'foobar');
+        $this->assertFalse($v->validate());
+    }
+
+    public function testContainsInvalidValue()
+    {
+        $v = new Validator(array('test_string' => 'this is a test'));
+        $v->rule('contains', 'test_string', array('test'));
+        $this->assertFalse($v->validate());
+    }
 }