<div id="wrapper">
    <ul id="myList">
        <li><p>1</p></li>
        <li><p>2</p></li>
        <li><p>3</p></li>
        <li><p>4</p></li>
    </ul>
</div>​

ul#mylist {
    @include reset-box-model;
    @include inline-block-list-container;
    margin: 0px auto;
    height: 180px;
    width: 640px;

    > li {
        @include reset-box-model;
        @include inline-block-list-item(0px);
        width: 130px;
        height: 130px;
        padding: 10px;
        margin: 0px 5px;
    }
}

(130px + (2 * 5px) + (2 * 10px) = 640px)) * 4 = 640px