For those of y'all who aren't gun people. A simple, legal, and excellent choice is Raid wasp and hornet spray. Shoots up to 20 feet, works like mace/pepper spray, and has no legalities attached to it.
Great idea, although to say there are "no legalities attached to it" is over-simplification. You purposely spray somebody in the face with wasp spray, and you can bet there will be legal ramifications, civil suits at least, however, you are right in that there are no prohibitions against carrying it.
What's more, it's easier for a hesitant person to decide to actually use it than to use a gun. Not only that, but it will be easier for a non-gun person to hit something with it, because you simply direct the spray until it hits the target. The bad part is that the cans are big and would likely be carried in the saddle bags, so getting it out in a hurry would be pretty iffy at best. I suppose one could make a horn bag-type holster for it to make it quick to get out.
Regardless, it's a great option for those who will not carry a gun, or for places where guns may be prohibited.
A gun in the hands of a person who is not practiced with it, or is hesitant to use it, can end up being worse than not having it in the first place.