var zipfile = require("zipfile");

1.Download or build from source zipfile module.

2.Place zipfile-iphone-x.y.z.zip file to /Library/Application Support/Titanium and unzip it.

//app.js: download zip from DropBox to Documents folder and extact file to Documents folder

// This loads the module for use in the JavaScript
var zipfile = require("zipfile");

Titanium.UI.setBackgroundColor('#000');

var win1 = Titanium.UI.createWindow({  
    title:'ZipFile test',
    backgroundColor:'#fff'
});

win1.open();
var xhr = Titanium.Network.createHTTPClient();

xhr.onload = function()
{
	var f = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory,'test.zip');
	f.write(this.responseData);
	Ti.API.log('INFO',Ti.Filesystem.applicationDataDirectory);
	zipfile.extract(Ti.Filesystem.applicationDataDirectory+'/test.zip', Ti.Filesystem.applicationDataDirectory);
};
xhr.open('GET','http://dl.dropbox.com/u/1400234/test.zip');
xhr.send();

	// This loads the module for use in the JavaScript.
	var zipfile = require("zipfile");

    var zip = zipfile.create("/path/to/zip/as/string.zip");
    zip.addFile("/path/to/file/to/add/filename", "path/in/zip/filename");
    zip.close();

	// This loads the module for use in the JavaScript
	var zipfile = require("zipfile");

    var zip = zipfile.open("/path/to/zip/as/string.zip");
    // This will return false if it does not exist. Now, add/update files to it
    zip.addFile("/path/to/file/to/add/filename", "path/in/zip/filename");
    zip.close();