CSS

div.selectbox {
    display: inline-block;
    *display: inline;
    zoom: 1;
    position: relative;
}

    div.selectbox a.select {
        border: solid #ddd 1px;
        display: inline-block;
        *display: inline;
        zoom: 1;
        width: 170px;
        color: #262626;
        text-decoration: none;
        cursor: default;
    }

        div.selectbox a.select span {
            padding: 0 22px 0 7px;
            display: block;
            height: 22px;
            background: url(img/icon_select.gif) no-repeat right 0;
            line-height: 22px;
            cursor: default;
        }
        
        div.selectbox a.select:hover span { background-position: right -21px }
        div.selectbox a.select_focus span { background-position: right -42px !important }
        
        div.selectbox div.pulldown {
            border: solid #bbb 1px;
            width: 170px;
            max-height: 150px;
            position: absolute;
            left: 0;
            top: 28px;
            background: #fff;
            overflow: auto;
        }
        
            div.selectbox div.pulldown a {
                border-bottom: solid #bbb 1px;
                padding: 5px 8px;
                display: block;
            }
            div.selectbox div.pulldown a.last-child {
                border: none;
            }
            div.selectbox div.pulldown a:hover,
            div.selectbox div.pulldown a.selected {
                color: #666;
                background: #eee;
                text-decoration: none;
            }

Script

jQuery(function($){
    $('div.selectbox').each(function(){
        var self = $(this);
        var select = $('a.select',self);
        var pulldown = $('div.pulldown',self);
        
        pulldown.hide().children(':last-child').addClass('last-child');
        
        select.click(function(){
            $('div.pulldown').hide();
            pulldown.show();
            $(this).addClass('select_focus');
            return false;
        });
    });
});

Demo