Right, made a few technical changes to how the site is run etc. to help try and prevent a complete fuckup like we've just had.
We now have daily backups of the whole site going of to Amazon's S3 storage option. It's all nice and automated etc. and S3 storage is pretty cheap, so shouldn't make much different to the costs of running the forum.
At some point I'll need to power down the forum to take a full server snapshot, but that's more about speed of restoring the site rather than maintaining data.