gistfile1.js

function one( foo ){
    return $.ajax({
        url: foo
    });
}

function two( bar ){
    return $.ajax({
        url: bar
    });
}

$.when( one('some-data.json'), two('other-data.json') ).done(function( dataFromFunctionOne, dataFromFunctionTwo ){
    console.log( 'stuff from two XHR:' + dataFromFunctionOne + dataFromFunctionTwo );
});