Question

How an access to the current object inside the call to data() or maybe any other jQuery function:

$('#newVisitors').data('options', $.extend($('#newVisitors').data('options'), {
   property : 'value'
}));

avoiding repeating of $('#newVisitors') selector?

Answer 1

You should store the jQuery object in a variable first;

var self = $('#newVisitors');

self.data('options', $.extend(self.data('options'), {
   property : 'value'
}));

Edit: If you want to use $(this);

$('#newVisitors').each(function () {
    $(this).data('options', $.extend($(this).data('options'), {
       property : 'value'
    }));
});