Hello to all :)! I finally got around to breadboarding the Atmega168 using only the necessary parts to get her up and running by following this fantastic tutorial ( http://itp.nyu.edu/physcomp/Tutorials/ArduinoBreadboard )! I loaded up the Auduino program with 5 pots connected to A0-A4 and a speaker to digital output 3! All perfect but I can't help feeling I'm supposed to add some diodes and some bits and bobs to make sure nothing fry's! Am I correct in assuming this? What is the general rule of thumb for inputs and outputs? 
Thanks, Goatboy
No that's OK. If the I/O was going to the outside world like a socket then you could add some protection:-
http://www.thebox.myzen.co.uk/Tutorial/Protection.html
If the I/O was going to the outside world like a socket then you could add some protection
Do you mean If I were using piezo sensors for inputs and solenoids for outputs for example? and if so would I still have to use some protective circuitry if I were using a servo? Thanks, Goatboy