Usage example ,  in your view file  use it like some other widgets!:

<?php
/**
 * Created by JetBrains PhpStorm.
 * User: yiqing
 * Date: 12-2-18
 * Time: 下午11:17
 * To change this template use File | Settings | File Templates.
 */
$this->widget('common.widgets.tag.tagit.JTagIt', array(
    'selector' => '#mytags',
));
?>

<ul id="mytags">
    <!-- Existing list items will be pre-added to the tags -->
    <li>Tag1</li>
    <li>Tag2</li>
</ul>
<div>
    <h5>example 2</h5>
    <?php $this->widget('common.widgets.tag.tagit.JTagIt', array(
    'selector' => '#mytags2',
    'options' => 'js:{ itemName: "user"}'
));
    ?>

    <ul id="mytags2">
        <!-- Existing list items will be pre-added to the tags -->
        <li>Tag1</li>
        <li>Tag2</li>
    </ul>
</div>
<div>
    <h5>example 3</h5>
    <?php $this->widget('common.widgets.tag.tagit.JTagIt', array(
    'selector' => '#mytags3',
    'options' => array(
        'fieldName'=> 'skills',
    ),
));
    ?>

    <ul id="mytags3">
        <!-- Existing list items will be pre-added to the tags -->
        <li>Tag1</li>
        <li>Tag2</li>
    </ul>
</div>


<div>
    <h5>example availableTags (Array) </h5>
    <h6>Used as source for the autocompletion.("c++", "java", "php", "javascript", "ruby", "python", "c")
     <br> you can type c/j/p/r..  to see the effect!
    </h6>
    <?php $this->widget('common.widgets.tag.tagit.JTagIt', array(
    'selector' => '#mytags4',
    // 'theme'=>'eggplant',    //remove the comment to see the another ui effect!
    'options' => array(
        'fieldName'=> 'skills',
        'availableTags'=>array("c++", "java", "php", "javascript", "ruby", "python", "c"),
        // event handler
        'onTagAdded'=>'js:function(event, tag){ alert("tag"+tag.html()+"  added!") ;}',
        'onTagRemoved'=>'js:function(event, tag) {
         alert("you want remove the tag!");
    }'
    ),
));
    ?>

    <ul id="mytags4">
        <!-- Existing list items will be pre-added to the tags -->
        <li>Tag1</li>
        <li>Tag2</li>
    </ul>
</div>

    <div id='msg' style="background: #c2973f"></div>
    <div>
        <script type="text/javascript">
            function addTag(){
                $("#mytags4").tagit("createTag", "brand-new-tag");
            }

            function removeAllTags(){
                $("#mytags4").tagit("removeAll");
            }

            function getAllTags(){
               var tags = $("#mytags4").tagit("assignedTags");
                //alert(typeof tags);
                alert(tags.toString());
            }

        </script>
        <h3>methods test!</h3>
        <div>
            <a href="javascript:;" onclick="getAllTags()">get all tags</a>
            <a href="javascript:;" onclick="addTag()">add tag</a>
            <a href="javascript:;" onclick="removeAllTags()">remove all</a>
        </div>
    </div>