Dreamhost says they keep regular backups of your files, but I always assumed that it meant there was some mythical backup temple that tech support could get at. Hidden away in their Knowledge Base is this little piece of information: there’s a .snapshot folder in your home directory. They don’t really advertise it.
Even if you think it’s not there (ls -a), it is. Go to that directory and you shall find hourly, daily and weekly snapshots of your files, for backupy goodness. I wish I had known this a few weeks ago.