Sometimes you need a specialized app to get the job done. For those trying to manage an iTunes library, SuperSync ($23, Windows and OS X) and iTunes Sync (Free Windows) can get the job done, but SuperSync is the only cross-platform option and it costs money. For those with folders, any syncing app will get the job done. Crashplan offers free backup and sync software for local stuff. It's certainly not the only thing you can use but one we really like.