The latest version of Application Loader is integrated with Xcode so you can deliver your binary directly from Xcode. For more information on this delivery mechanism, please review the iOS Development Guide.
Also, if you have installed iPhone SDK 3.2 or later, you can access Application Loader from your Utilities folder (/Developer/Applications/Utilities/Application Loader.app).
Application Loader can also download from iTunes Connect within the Manage Your Applications module.