Julia, your link is not working because of the comma.
Peter, there are a few different approaches to this issue, and you will find information from Ed about it in his articles. What I have found to be effective for my pet dog (I do not participate in SchH, so I am not any sort of "expert" in this area, but I do have some hands on experience with dog aggression in my pet dog) involves controlling the distance from other dogs while working her in obedience, using tons of positive motivation/reward, while slowly, over a long period of time, decreasing that distance.
Does your dog flip out just seeing another dog on the horizon, or is there a distance at which he can see another dog but not be flipping out?
I would set up structured training exercises using someone else with a calm dog. Position yourself maybe 100 feet (about 30 meters or maybe even more for insurance) from the corner of a building, get your pup working happily, and have the other person come around the corner with their dog and stand there for about ten seconds. During this time, get your pup focused on you, heeling, sitting, etc., and reward the crap (pardon my language) out of him for every correct response. After about ten seconds, the other handler goes back around the corner, out of sight, and you go neutral. Your pup gets no more attention or rewards, etc. After about a ten second pause, repeat the process again, a total of three or four times, then be done for the day. Over time, after maybe four or five separate sessions, you should start seeing an improvement in your pup's responsiveness and attentiveness to you with another dog in sight.
There should be no barking or lunging or growling, etc. If you do have any of these things, then increase your distance from the corner of the building, until you are at a distance where your pup can see the other dog come around the corner, but can still respond to you. If he won't take salmon from you, then you're too close and need to increase the distance. If he locks onto the other dog with his eyes and will NOT look away, you're too close and need to increase the distance. Your pup should be able to see the other dog, look away from the other dog to look at you, take food, and follow easy commands that he already knows.
You'll need to practice with a lot of different dogs so that your pup will generalize the information. Also, you might need to work at different distance with different dogs. Your pup might get used to one particular dog at quite a close distance, but if you introduce a new dog into the training, go back to your original distance and start working from there.
Basically, if it were me, I'd treat it like an "obedience under distraction" type of exercise, by first keeping the distraction at a low enough level that the pup can handle it, and as the pup's tolerance increases, make the distraction a little harder for him in teeny tiny increments.
This is just what *I* would do. Others may suggest a different approach for you.
Lisa & Lucy, CGC, Wilderness Airscent
Western Oregon Search Dogs