
Soo many replies! Thanks for the input everyone.
The general consensus seems to be that neutering will make no difference or potentially make things far worse then. I have spent some time Googling and general opinion on many other forums/message boards seems to be the same. I did find a few cases were people have found that neutering their dog HAS made other male dogs react more positively to them, but I have no idea whether these were nervous dogs or not (lucyandmeg - what was the dog at your flyball class like?). We have a vet appointment next week for something unrelated but I'm wondering whether I should even mention this at all now. He's not the kind of vet who pushes treatment or medication etc on you but I'm not sure whether I should even consider castration anymore, chemical or otherwise.
Tenaj - Control Unleashed is one of those books I've been meaning to read but not got round to it. He is clicker trained. To be honest though I've actually started doing the opposite of what you suggest - I try and get Talli to stay focused on me if I spot a strange dog I'm unsure of incase he catches the gaze of the other dog, who might consider his looking at them as "rude" or some kind of invitation to come over. I prefer it when I can sneak us both past another dog with neither dog being aware! I thought this was for the best for now. What do you think?
The Cautious Canine is another one I've been wanting to read. Does anyone know if it would be worth getting that as well?
freelancerukuk - I think you've hit the nail on the head with all you've said. The majority of other dog owners do seem to be completely ignorant to the warning signs their dog is giving off and their dogs have no recall to boot. Breeds that my boy has been attacked by include a male Boxer (intact), male Black Lab (intact), male Old English Sheepdog (not sure on this one), 2 male Staffies (one was intact, not sure about the other), male Weimaraner (intact I think), male Patterdale (intact). He has also been charged at, lunged at and bulldozed into by countless others, several of which have meet the end of my foot or stick. Over the last couple of years there seems to have been an influx of rather nasty male Black Labs for some reason. He also gets mounted a lot by other intact males. Thankfully we don't seem to have too much of a problem with the "fighting" breeds where I am. I can't say I've had much of a problem with females at all. The majority of them seem very taken with him if anything and I know one who is iffy around neutered males, but fine with Talli. [Apologies to people who have nice dogs of the above breeds!]
Usually at this time of year I would be doing just the one off lead walk in the morning and then a pavement walk in the evening when it's dark. Unfortunately he was recently diagnosed with arthritis in the outside toe joint of his front right foot. This means that I'm very limited in the amount of walking he can do on hard surfaces as it causes the joint to swell. He's fine on soft ground and we can be out for a good couple of hours with him running around with no ill effects, other than my blood pressure going sky high. We do play search games in the garden and he loves to retrieve. Maybe I will just cut the second walk out for now.
Going back to a training class would be a good idea. We went initially from when he was 12 weeks old until he was about 2, and ringcraft classes we started when he was 11 months and went there until he was about 3 (purely for the fun and socialisation, would never breed). When I think of all those intact males there and barely a cross word between any of them. Talli was much more confident then and not worried by the close contact of other entire males standing behind and around him etc.
I think part of the solution is that I need to drive! Unfortunately (a phrase that seems to apply a lot to me) I can't even afford the lessons, let alone the running of a car. Until then I think I will have to just continue to try and avoid the busy times and busy areas of the fields. We saw his whippet friend again this morning and the walk went without incident, other than passing a man on the way home who almost put on a ski display when whilst trying to hold back two lunging Bull Mastiffs on wet muddy ground

. Next week we're hopefullly meeting with his Greyhound and Lurcher friends some mornings.
Wizaid - so sorry you are experiencing similar problems. How terrible to have 3 incidents on one walk! I really feel for you. It wouldn't be so bad if we had rude, in your face dogs, who needed a telling off but when they are so innocent it is especially hard to watch. I hope it doesn't change your boy. Sometimes when I have a run of not having incidents I start getting my confidence back up, but the places I walk seem to be unpredictable in terms of who else will be there. Hopefully if you only have incidents on Sundays you can just avoid that particular place for the day! Hope you don't have any more problems x
Thanks again all for the advice and ideas. Didn't get online til rather late so hope I mostly make sense!