We own a lovely lively 17 month old chocolate labrador, we wondered if there was any thing we could do to stop him pulling and barking when he spots other dogs, once he has met them he just wants to play and is very friendly.

Find a training class and take him along. If you dont know of one look at www.apdt.co.uk they list classes all over the UK

I would suggest you introduce him to a headcollar, there are lots of threads on the subject and visitors regularaly post looking for help with their dogs pulling. Pet shops sell headcollars under names like Halti or gentle leader, they do work and give you alot more control, lots of lab owners use them. They can also help with barking because you can control the head, the headcollar will allow you to approach people calmly and if they are happy to let your dog talk to them then you can let him say hi, a good idea is to have a command or realease that indicates that he is free to socialise, something simple like OK is fine, you are signalling a release to your dog so that he knows without the release he should stay beside you and do nothing.
I think classes would be a great idea, choccie labs can be excitable and extra socialising and training are a great idea.
If you want extra info on headcollars then post a question about headcollars and labs, you will get lots of praise for these products.