Help with Growl

[James Austin]

Hi folks,

Could someone please give me some help with Growl? I am currently  
running 0.7.6.

Firstly, could someone please give me a comprehensive overview of  
what it is and what it does, and secondly, i've heard that you can  
get Growl to tell you when external devices are connected, how do i  
go about setting this up.

Thank you

Take care

James