Best way to manage costly scrolling in JavaScript?

// need to have this variable outside the scope of the handler defined below
var timeoutId = null;

// think of "connect" as pseudocode for whatever you use to connect handlers
connect(widget, "onscroll", function() {
    // ...scrolling...
    if(timeoutId != null) clearTimeout(timeoutId);
    timeoutId = setTimeout(function() {
        // *probably* done scrolling, it has been
        // 1 second since the last scroll...
        // run your code to render current position here
    }, 1000);
});