Lately I've found myself fascinated by the depressing tale of
Diary-X. The site crashed almost a year ago.
No diaries could be retrieved -- the most recent backup had been done in 2004 (!) and turned out to be damaged besides. There was
much sorrow over this. The site had offered a backup function for awhile, but few members took advantage of this.
What would break
your heart if it couldn't be retrieved? Threads on a discussion board? Old email? Your latest journal layout? Browser bookmarks?
Save it.
Use whatever functions you have. Check any
FAQ your blog or website host has to see what backup/export option(s) they offer. Use File -> Save As in your browser menu to painstakingly save one webpage at a time if you have to. Search message boards for all posts by you so you can save each one. If you run a site that uses a proper database like MySQL, that's the first thing you should backup (
here's a walkthrough). Whenever possible, send backups to your web-based email (like Gmail or Hotmail) -- that way, even if your websites AND your computer implode, you can still reach your data! -- and
never rely on your webhost's backup. Usually they just save over the last backup, so if something gets corrupted between host backups, there's no way to get the working version back.
Backup now -- don't put it off. Do it because you don't need to. By the time you realise you need a backup, it's usually too late.