I accidentally deleted a bunch of non-spam tickets via the bulk update interface. I was really happy to see that RT doesn't delete anything from the database, so I could just browse to the ticket numbers directly and change the status back to "open".
Unfortunately, I couldn't find a way to search for deleted tickets and get the list of IDs that needed to be restored. The "deleted" status is missing from the list of criteria that can be added in the Advanced Search. I had to look in the database directly, something I could not do if I didn't have access to the DB.
My suggestion is to add the ability to search for deleted tickets. It would greatly help users restore their lost tickets when they screw up.