Recall Training Advice

Question
I am currently training our 5 month old black labrador retriever, and would be very grateful for any tips on recall training, as he is quite good a lot of the time, but when distracted by something else, goes completely "deaf" to any recall demands, and just continues to do what he is doing at the time.

Answer
5 months is a bit young to expect perfection.  That's the prime age for distractions and testing mom/dad to see if commands really need to be obeyed or not.

I would take the time to reinforce the behavior of COME as see in this video:
http://www.youtube.com/watch?v=eUFrJiBSk3Q

Also, if you know the dog might get distracted, never let him off lead.  Use the long line, use a long flexi, just don't let him off lead.  Keep in mind that you do not want to give a command more than once (nagging is bad) and don't give a command if you can't correct it if they do it wrong or ignore it.  

You will have to start from the beginning and re-teach COME so that he knows the "right" things about the command.  I would also use alot of treats.  Our dogs have a large yard to run in with dog friends on 3 sides.  I was able to teach my young pups to come quickly because they LOVE cookies.  Be liberal with the treats when you are training!  Bribery is OK when training young dogs.  

See if any of that works.