var options = {
url:'/_layouts/YourAspx/YourPage.aspx',
title: 'Your Application Page Title',
allowMaximize: false,
showClose: true,
width: 700,
height: 260,
dialogReturnValueCallback: RefreshOnDialogClose
};
SP.UI.ModalDialog.showModalDialog(options);
Key here is the callback function; set it to RefreshOnDialogClose. Dead simple ;-)
