Once or twice a quarter I'll end up with a relatively mechanical task that I can do with a keyboard macro, query-replace-regexp/dired-do-find-regexp-and-replace

Once or twice a quarter I'll end up with a relatively mechanical task that I can do with a keyboard macro, query-replace-regexp/dired-do-find-regexp-and-replace. That normally saves me at least 30-45 minutes compared to either doing it manually or writing a script.