$('.widget-item-expand').click(function() {
        $(this).parent().toggleClass("selected");
        var currentId = $(this).parent().attr('id');
        var currentIdfull = "#"+currentId+"-full";
        $('#port-full-item').css("height","320px");
        $('#port-full-item').slideDown('slow');
        $(currentIdfull).css("height","320px");
        $(currentIdfull).fadeToggle('slow');
});
​

if ($('#elm').is('.selected')) {
//#elm has the class
} else {
//#elm doesn't have the class
}

$('.widget-item-expand').click(function() {
    $(this).parent().siblings('.selected').removeClass('selected');
    $(this).parent().toggleClass("selected");
    $('#port-full-item')
        .addClass('selected')
        .css("height","320px")
        .slideDown('slow');
    var currentId = $(this).parent().attr('id'),
        $prevFull=$(".widget-full.selected");
    if(currentId+'-full'!==$prevFull.attr('id')){
        $prevFull
            .hide()
            .removeClass('selected');
    }
    $("#"+currentId+"-full")
        .addClass('selected')
        .css("height","320px")
        .fadeToggle('slow');
});