Windows/Mac: Free application Docstoc Sync automatically synchronizes files between your desktop computer and previously mentioned document sharing web site Docstoc. Once installed, the application monitors your documents folders and automatically syncs any changes you make. Documents can be uploaded as either public or private (any file in your My Documents folder defaults to private), which means you can use the app to either share docs on the web or back them up privately. Docstop Sync is freeware, Windows and Mac only.