Starting a program when plugging in an external disk?

[Avi Schwartz]

Hi,


I have an external USB disk drive which I would like to use to backup 
one of my computers.  I would like for a program (for example "rsync") 
to be started automatically when I plug in this disk to do the backup 
and then unmount it.  It should do it only if this specific disk is 
plugged in, and not when others are plugged in.  Is this possible?


Thanks,

Avi