Sometimes you just gotta centre this bitch.

center_this_bitch.js

// Courtesy of http://www.chupamobile.com

function center_this_bitch(target, context, animate) {
    var top, left, context_target;
    animate = typeof animate !== 'undefined' ? animate : false;
    switch (context) {
    case'parent':
        context_target = target.parent();
        top = ((context_target.height() - target.height()) / 2) + 'px';
        left = ((context_target.width() - target.width()) / 2) + 'px';
        break;
    case'window':
        top = ((user['window-height'] - target.height()) / 2) + 'px';
        left = ((user['window-width'] - target.width()) / 2) + 'px';
        break;
    default:
        top = ((context.height()) / 2) + 'px';
        left = ((context.width()) / 2) + 'px';
        break;
    }
    if (animate == 'animate') {
        target.animate({
            'top': top,
            'left': left
        });
    } else {
        target.css({
            'top': top,
            'left': left
        });
    }
}