For my WordPress blog, which uses MySQL, I just do a MySQL dump, which makes a copy of the DB, which can be imported later on as a backup solution. Here's a write-up that shows how to use the mysqldump command as well as using phpMyAdmin to create the backup.
For my web site files I actually use SVN (Subversion) so I always have a backup if need be, but I also occasionally just make a copy of the folder and archive it in a zip.
Also for Wordpress you can install plugins like WordPress DB Backup. It has some nice options like automatic scheduling, e-mailing you the DB, or storing it in a specified directory.
unfortunately, i'm referring to blurty, which is a dinosaur when it comes to the 'backend' access, so i can't use any of the suggested solutions. maybe some of the livejournal tools out there would work, since blurty is a lj clone.
i also use wordpress.com, which is nice. wished my community of friends would move from blurty to wordpress. 🙂
I wasn't talking about "upgrading" the service (whatever that means)- I was saying that you should ask blurty and inquire how you would go about backing up your site (if it's even possible). I'd imagine they have regularly scheduled backups of their databases on the server end of things, but it's nice to have a bit more control.
sorry, i meant that for them to add anything to support solutions similar to your suggestions seems to be practically impossible.
they do have an export feature which i already use, and the resulting backups are csv or xml files. probably useful for migrating to another service, but i wish to have just a cloned local copy and i'm just wondering about all options before i settle on sitesucker.