Automattic, the folks behind WordPress are working hard on VaultPress. A service that allows webmasters to backup their blogs in real-time. It will be a paid service on launch that will cost $25 or less per month.
Here is how it works, you sign up for the service and install the plugin. Everything will then be backed up in real-time, including comments and small revisions. Apart from backing up the blog, it will also patch critical bugs by push updates automatically and alert you of any suspicious activity or hacking attempt.
Your data will be stored both locally and on two different locations on the cloud. If you have a large blog, I would recommend applying for beta. It is always better to be safe than sorry.
Even though, I have multiple backups; one on my local Home Server and one in remote location (managed by Liquidweb), I have signed up for VaultPress because it is tightly integrated with WordPress infrastructure.
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