How often/fast should I be doing JSON requests?
I'm using the following code to constantly keep my UI accurate.  I dislike the slight one second delay though.  It only returns a small JSON file with only a few keys.

Here is what I've been using:

    function parseDynamicData(ard) {
        //update UI
        $('#track-title').html(ard['song']['title']);
        $('#track-artist').html(ard['song']['artist']);
        $('#track-album').html(ard['song']['album']);
        $('#track-art').attr('src', ard['song']['art']);
        if (ard['details']['playing'] == 'true') {
            $('#control-pauseplay').html('Pause');
        } else {
            $('#control-pauseplay').html('Play');
        }
    }
    
    function updateLoop() {
        $.getJSON('/jtrack', function (data) {
            parseDynamicData(data);
        });
        setTimeout(updateLoop, 1500);
    }
    
    $(document).ready(function () {
        setTimeout(updateLoop, 1500);
    });

At what point would setting the timeout as less become problematic?  I'm running this on mobile devices (such as the iPhone or Android) so I assume I need to not do it all too often.
How often/fast should I be doing JSON requests?
===

I'm using the following code to constantly keep my UI accurate.  I dislike the slight one second delay though.  It only returns a small JSON file with only a few keys.

Here is what I've been using:

    function parseDynamicData(ard) {
        //update UI
        $('#track-title').html(ard['song']['title']);
        $('#track-artist').html(ard['song']['artist']);
        $('#track-album').html(ard['song']['album']);
        $('#track-art').attr('src', ard['song']['art']);
        if (ard['details']['playing'] == 'true') {
            $('#control-pauseplay').html('Pause');
        } else {
            $('#control-pauseplay').html('Play');
        }
    }
    
    function updateLoop() {
        $.getJSON('/jtrack', function (data) {
            parseDynamicData(data);
        });
        setTimeout(updateLoop, 1500);
    }
    
    $(document).ready(function () {
        setTimeout(updateLoop, 1500);
    });

At what point would setting the timeout as less become problematic?  I'm running this on mobile devices (such as the iPhone or Android) so I assume I need to not do it all too often.