I'm probably a hypocrite, too? Owning a young Aussie (and being an Olde Pharte myself) means I can not adequately exercise 45-lb Augie when he must be constantly on a leash when we winter in FL. Therefore, we go to our local dog park several times each week - we tend to go in the late morning when there are fewer dogs. That being said - Augie is super-social, and simply wants to find a buddy to run with. His energy level tends to attract other herding breeds (who "get" him, as Mark points out) but pitbulls and "doodles" seem up for a good game of tag with a crazy dog, too. Ben, my 20 lb miniaussiedoodle, "identifies" as a large dog, and if the big-dog side of the park is a "friendly mix", I allow him to play there. If I see dogs with high prey drives, Ben goes in the small-dog side for a game of fetch.
But when we're out-and-about, I generally don't let them socialize unless it's a dog/owner we have experience with. The people who go to our dog park are "dog people" - their dogs are well-trained and socialized. The general public (even campers) - maybe not so much. I figure it's my job as dog mom to make sure my dogs don't have a scary experience.
I also have to add that last year, Ben picked up Bordetella at the dog park - apparently a variant that got past his yearly vaccination against that virus. It was mild and lasted about a week - but points out that socializing also carries risks if your dogs aren't FULLY vaccinated. (I also opt for dog flu vaccinations)
