so on the click event, when I call the function getFavicon(), it works, but on the very next line when the timer is supposed to call it it doesn't work.

Firebug says

getFavicon is not defined
checkUrlFaviconTimer = setTimeout("getFavicon()",200);

//Favicon 
    function getFavicon() {
        $.get('/homepage/getfavicon.php', { url: $('add-link-url').val() }, function(data) {
            alert(data);
        });
    }
    
    var checkUrlFaviconTimer;
    $('input[name="add-link-url"]').click(function() {
        clearTimeout(checkUrlFaviconTimer);
        getFavicon();
        checkUrlFaviconTimer = setTimeout("getFavicon()",200);
    });

Figured it out!

I think it had to do with the scope of the functions. I moved the getFavicon function out of my jquery $(document).ready (it didn't really need to be there anyway) and it now works.