Plugin para Upload com Ajax (IE não suporta)

gistfile1.js

var formData = new FormData() || false;
$.fn.uploadIntra = function(callback){
    var elem = $(this).get(0);
    var i = 0,
        len = elem.files.length,
        reader, file;

    for ( ; len--; i++ ) {
        file = elem.files[i];

        if ( window.FileReader ) {
            reader = new FileReader();
            reader.onloadend = function (e) {
                console.log(e.target.result);
            };
            reader.readAsDataURL(file);
        }
        if (formData) {
            formData.append("files", file);
        }
    }
    if(formData){
        callback(formData);
    }
}

//Exemplo de uso:
$(':file').on('change', function(){
    var $form = $(this).parents('form');
    var action = $form.prop('action');
    $(this).uploadIntra(function(data){
        $.ajax({
            url: action,
            type: "post",
            data: data,
            processData: false,
            contentType: false,
            dataType: 'json',
            success: function(data){
                console.log(data);
            }
        });
    });
});