To follow all AJAX calls on an HTML doc, you can overwrite the XMLHttpRequest prototype.
This way, you can watch for actions on methods of XMLHttpRequest objects.

Here's a small sample code :

var open = window.XMLHttpRequest.prototype.open,

    send = window.XMLHttpRequest.prototype.send,

    onReadyStateChange;



function openReplacement(method, url, async, user, password) {

    var syncMode = async !== false ? 'async' : 'sync';

    console.warn(

        'Preparing ' +

        syncMode +

        ' HTTP request : ' +

        method +

        ' ' +

        url

    );

    return open.apply(this, arguments);

}



function sendReplacement(data) {

    console.warn('Sending HTTP request data : ', data);



    if(this.onreadystatechange) {

        this._onreadystatechange = this.onreadystatechange;

    }

    this.onreadystatechange = onReadyStateChangeReplacement;



    return send.apply(this, arguments);

}



function onReadyStateChangeReplacement() {

    console.warn('HTTP request ready state changed : ' + this.readyState);

    if(this._onreadystatechange) {

        return this._onreadystatechange.apply(this, arguments);

    }

}



window.XMLHttpRequest.prototype.open = openReplacement;

window.XMLHttpRequest.prototype.send = sendReplacement;

With this sample, for every AJAX call you'll have a warning in the JavaScript console.

It's not jQuery script, but you can use jQuery inside as you want.

This solution probably won't work on IE 6 or older, but it works in FF, IE7+, Chrome, Opera, Safari...