Useful app: I have 3 external disks I would like to have attached, but not monted. Semulov makes this easy, mount and unmount them when needed.
I have the feeling there is a small but, though: after running Semulov, and after, firewire disks are not mounted and, from that moment on, with Semulov running or not, they are not mounted any more. Am in ML 10.8.2. The workaround seems to be simple: to replace FW connection by USB connection.