Some things I do with my dogs and puppies:
* Schools at bell time. Sit outside the gate and let the kids pat the puppy. Doubles as a good way to teach children how to approach dogs.
* I always try and find fireworks. I've even taken a litter of puppies to fireworks at six weeks of age (in a crate in the back of a car). For my last litter our suburb was considerate enough to have them just a few streets away when they were seven weeks old.
* A speedway or dirt bike competition. Very loud, smelly and dirty.
* Horses or stables if you know someone who owns one. Get the dog used to being around horses. Ditto for cats, chickens, cows, and other birds.
* Markets with lots of people milling around and the dog has to calmly walk through the crowd at heel and not pull on the lead.