BackupBuddy

BackupBuddy allows you to backup, migrate, and restore your entire single or Multisite WordPress install including the widgets, themes and plugins. To keep your backups safe, BackupBuddy supports sending your backups offsite to Amazon S3, Rackspace Cloud, Dropbox, FTP, and email. Quickly and easily restore your site on the same server or migrate to a new server with a different domain and database. The process is easy, fast, and reliable.