Many dogs have no sense of whether or not to approach a person: sometimes they will get patted, sometimes not, individual stances can probably not be read well enough by the dog to know the outcome in advance. Some people are truly frightened by dogs, some simply fear to be slobbered by an especially enthusiastic dog. Dog owners usually fail to react as well.
So i propose a shoe add-on (inlay, or small screwlike object to be fastened in the sole), that emits a distinct ultrasound sound while walking normally - thus a dog can detect any wearer of such at a distance. If the wearer feels threatened by a dog, or simply wants it to clear the vicinity, a simply grinding motion with the heels emits a far more powerful ultrasound noise, uncomfortable for the dog. Thus, the dog can learn in it's own terms which humans are better left alone.-- loonquawl, Sep 03 2009 [21_Quest]: At least one for every visit to a public park or woods... Seems dog owners over at your town are a lot more considerate - the gadget would not take off there...
The idea was two-tier for the exact purpose of not randomly annoying dogs - a sound that is simply recognizable, but not disturbing, so dogs can relate the disciplining for jumping up to something prior and are enabled to learn not to jump up at those strangers.
All this would of course be avoidable with good education by the owners, but that would have been a let's all, so i out-sourced it to the interested party.
This is not about not wanting to be near dogs, shunning their sight, praying for their non-existence. It is simply the attempt of a solution for being slobbered and dirt-pawed by random dogs that have owners too lazy for some stringent education and that have no learning experience during the act.
The products on the market are for a more escalated problem, and do not offer the dogs the constant prior warning, which is the main point in my idea.-- loonquawl, Sep 04 2009 Might be handy in parts of the world where the dogs simply roam the streets.-- RayfordSteele, Sep 04 2009 random, halfbakery