Zakari:
Hey dude, thanks for your reply.
Ok I found the blink without delay tutorial so I now understand what you are talking about. Though I still have some questions. From what I have read it isnt possible to get an arduino to do 2 things at once. (I seem to remember this being easy with a picaxe?) so I cant have it constantly checking the sensor whilst it is fading the leds? I always have to wait for it to finish a cycle?
Exactly at the same time? No, but it can do it fast enough for the human eye to not know the difference.