I saw this post on BackupMyBlog. This is is a service that will backup data from you blog, so you can have redundant backups just in case the host becomes unavailable. If you want to use this service, you install a php script. It works by dumping the contents of your mysql database.
If you use this, make sure that you are careful of a couple of things.
- Make sure that the user that you specify a mysql user that only has read-only access to the databases used by the blog. Update: The user will need write access to restore a backup
- Often blog software store the passwords used to log in in the database. You should probably make sure that this doesn't get backed up. (You can do this by making sure that the mysql user doesn't have access to the table that stores the passwords.)
- The backup service could use the rss feed to get the contents of the posts.
- The entries in the rss feed contain a url to the comments for that post. The templates can also be modified to allow the comments to be identified easily.
This type of system would make sure that only the data that is publicly available would be backed up. Also, this would work with blogging hosts like Blogger.