Firstly, can anyone give any suggestions as to what is nice to stuff a Kong with. My dog eats Bakers Dry Food at the moment.

Secondly, Brody is 1 year old (today actually). We kept him in a large crate overnight / whilst at work (part-time/3 days a week), whilst he was a puppy who liked to chew the furniture! However, about a week ago, we decided to let him have a free run of the kitchen/dining room, which he obviously prefers. Unfortunately, he has now started to wee during the night, or when I am out at work - it was never a problem in the crate (I assume because he did not want to mess in his own bed). He is not left for any longer than 8 hrs on a night, and no where near as long during the day. My problem is, as I know he is capable of holding it, how do I stop him from doing it, without even catching him in the act so to speak.
I do not want to put pee-pads down as a) I dont think it should be seen as 'ok' at his age, and more importantly, he would rip them up and EAT them before they were ever used for their purpose.

I would appreciate any advice as soon as possible, as I dont want this to become 'habit' and 'the normal thing to do'.

I'm afraid I can't advise you on the accident problem however Glazby loves bread and butter, or peanut butter, chocolate crunchies (from pet shop), I put bits of bannana in there - basically anything he likes will go in - he then has hours of fun rolling it around the floor trying to get it out!!

Dogs are very much creatures of habit and I wouldn't change his routine.  I'd go back to using the crate. 
Sally

http://www.takingthelead.co.uk/2/Health/kong_stuffing.htm

I would reconsider what you are feeding your dog as well, Bakers is full of salt, sugar and food colourings all completely unnecessary for a dog.  Perhaps Burns dry or Naturdiet wet?