BackupBuddy WordPress Plugin:
Backup your entire WordPress installation in minutes with this WordPress Plugin. Widgets, themes, plugins, files and SQL database – the entire package!
Just like your laptop or desktop computer, you should be doing regular backups of your website. With BackupBuddy you can schedule backups and have them sent off-site to Dropbox, Amazon S3, Rackspace Cloud or your email. Or download them right to your desktop.