How to run Applescript on Disk mount

I want to run an Applescript when I mount a specific disk. It isn't if the script is located on the disk or not, it should just run when OS X mounts the disk.

I tried to accomplish this with folder actions, but it looks like it isn't possible to do it this way.

Clarification:

1. I get home with my Macbook
2. I plug my USB Hub into the device
3. External disks are mounted in OS X
4. My Applescript gets run, does some stuff on those disks

I want to automate step 4.

You don't mention under which context you are mounting the disk, but what about going the other way and mounting the disk with the Applescript?

I mention context because when mounting a disk with Applescript is the big caveat that if it is a network volume, and the network is password-protected, then the user name and password would have to be stored as plain text in the script for a seamless execution.

UPDATE: A bit of searching found a similar question elsewhere. Essentially, a script can be made to do this by applying the script as a Folder Action to /Volumes:

on adding folder items to this_folder after receiving these_items
    repeat with aItem in these_items
        tell application "Finder"
            if (local volume of aItem) and (name of aItem is "[Name of Hard Drive]") then
                -- do something with the drive
                -- eject aItem
            end if
        end tell
    end repeat
end adding folder items to

The likely most robust solution is to create a launchd job with the StartOnMount property set to -boolean YES:

StartOnMount <boolean>
This optional key causes the job to be started every time a filesystem is mounted.

This is how Time Machine does it (see /System/Library/LaunchDaemons/com.apple.backupd-attach.plist).

Use a Finder FolderAction that monitors /Volumes. When a new folder appears, that means a new disk has been attached. Now your FolderAction can run an Automator action, AppleScript, or shell script to do your thing.