Gentlemen, thinking about the OP, I had some thoughts I' like to add to this discussipn.
What is leagal everywhere, has no backlash at all, can be carried by anyone?
There is only one tool in the self defense arsenal that fits this description. I'll explain.
As I mentioned in another post not too long ago, I'm a member of a depression group that meets at the V.A. hospital in Washington D.C. once a week. I'm the only white guy there, me being from the outer suburbs of Germantown Maryland. Most of my fellow vets are African-American from the local area of Washington D.C. Not some of the best parts either. Low income, high crime inner city getto areas. Most of my fellows in our 8 person group have had records of jail time, drug problems, and a few hard case prison terms. Convicted fellons from southeast D.C. Irving street, 8th street.
Over a few months one can't help but to get to know each other, and over a few coffees at the coffee bar in the lobby, we talk. Very gradually the barriers have come down a great deal, in spite of our different backgrounds, after all, once we were all soldiers in the same war. Common memories there. Now we have a common problem.
The one I think is the Forrest Whitticker look alike, Harvey, and a few others have developed a habit of after our session, of meeting together for a coffee downstairs and just talking. The subject came up a month or so back about self defense. A subject they are very interested in given where they live.
It was pointed out to me, while I had noticed, the vast majority of men at the V.A. carried a stick. This varried from the standard crook top cane handed out by the V.A. to rustic rough walking sticks that looked like they had been crudely made from about half an oak tree. Charater sticks. Rough finished, with bends and crooks in the them, some sanded down to a nicer finish with Arican symbols and figures carved or burned into them with a small fine soldering iron. Some very nicely done. A few here and there were only a short strait staff of a stick, barely more than a sawn off tree limb of stout proportions.
Now this was a V.A. hospital, so I took no notice of the sticks. After all, there was alot of us old Viet Nam vets limping around with various old injuries giving us problems, and a growing number of younger Gulf war vets coming in. But it was Harvey that pointed out something to me. He told me to watch them coming in. Only then did I realize that a very great number of them did not appear to need a stick at all. They would stop at the newspaper machine by the door and buy a paper, place the stick under thier arm and continue to walk across the big atrium with no limp at all while looking at the paper. Or they'd tuck the stick under thier arm while buying a coffee and walk off with the stick still tucked under thier arm, walking perfectly normal.
I was sitting there with "Harvey", "Charles", and "Moody" and they filled me in.
These men had no physical need of a cane, but they walked the mean streets of Washington D.C. living in bad nieghborhoods. And they all had a very stout rustic stick. The stick was sending a message. Apparantly the weapon of choice in D.C. for street muggings is a kitchen knife. Something like a large paring or short boning knife. This is for a couple of reasons. One being its cheap. It can be stolen from home by a juvinile, or swiped from a discount store, and its shiney and pointy, and will work at its intended task. Task being, intimidating a victim into giving up his wallet and cell phone. The knife works, because they pick thier mark carefully, work at "in your face range" and when they run off they toss the knife down the sewer along with your cell phone and wallet once they remove cash from the wallet. They only want your cell phone to cripple your attempts to call the police fast, giving them a bit more lead time. They only need a few minutes. Getting caught with a cell phone that is not yours can be a problem if you have a record.
Guns are a valuble tool for robbing a liquor store or convienence store, but considered too valuble to a street punk for a simple mugging. The Glocks come out for drug turf wars, druggie on druggie crime, and drive bys to hit a rival gang member. Since most gang members are convicted fellons, they are very concious of keeping the gun hidden till they need it. Lower etchilon street punks use a knife. Its cheap and effective, and disposable. No fuss, no muss.
So the older reformed guys carry a big stick, as a message to the street punks that if you try to take them, theres going to be a beat down. Go away. The stick is carried by guys like Harvey who have a record, can't afford to be caught with a weapon, but needs something since they live in a rough 'hood. No laws anywhere about a walking stick. But it gives them a tool to use. It buys them distance, blocking ability, and longer range strike ability. But most of all it's a visable flag sending a message to the right people, try me, but there's going to be a fight.
I thought about that, and recalled a while back when three latino street types backed down from me in Frederick Maryland. They had moved to bloke my path on a backstreet sidewalk, but when I changed my grip on my knarly blackthorn stick I use, and got ready to start swinging, they moved aside. Three late teens-early 20 punks backed down from a white haired senior citizen with a stick. They knew there was going to be a fight, and they didn't want my wallet that bad.
After my talk with the guys, I had to drive accross town to meet somebody, and I noticed as I drove through some not so good 'hoods, the large number of African-American men in D.C. carrying a stick. It had never really registered on me before, but in every nieghborhood there was at least one or two guys on every street carrying a stick. Not using it to walk, just carrying it. Not caring what anyone thought. Just going about thier life, and carrying stick just in case of something.
I can't think of ANY other tool that can be carried, stored, transported ANYWHERE, than a stick of one form or another. Even onto airlines and into court houses. If your over 40, nobody gives you a second glance. If your a young guy, tell them you messed up your ankle in that rugby game last month and it still bothers you on stairs. Or you dumped the dirt bike and it still bugs you a little on stairs or uneven surfaces. Some activity you're known to do. After a few weeks it will become such a part of you, it will not even be noticed. People adapt to changes very quickly. If you don't make a big deal out of it, they won't. Most young guys feel self concious and blow it because of what they are feeling, not from external flack. If you stick it out, (okay, bad pun!) it will just become part of your persona. If somebody says something to one of your friends, "Why is so and so carrying that cane around?" it will just come out that "Oh, he messed up some tendon or something in a soccer game."
Carry the stick/cane around and in a few weeks it will become part of you. The feeling of awkwardness will fade, and you won't be stumbling over it, forgetting it, or self concious about it.
So leave the jack handle in the truck, the crowbar in the tool chest, the machete in the garden shed. You can move a piece of hickory faster than a steel tool that is too heavy for good fighting. Have a cane or stout walking stick in your car and take it with you when you get out, and a nice heavy hickory or hornbeam hiking stick or short staff handy in your dorm room. Travelers on the byways of medieval Europe did very well against robbers by using a quarter staff and knowing how to use it. The old guys in Asia did very well too, using staffs. The famed samuri Musashi killed some of his enemys with a wooden training sword rather than a steel one. This opens up a world of possabilities. Training with a boken is not hard to come by, and the training is in your head forever. Nobody can ever take it away, or tell you that you can't carry it. The knowledge in your head, plus a stick/cane can go ANYWHERE with you. If you don't have a stick, one can be gotten anyplace. You can even cut down a nice strait sappling and have one imediatly. Yank a towl bar off a wall, kick a rung out of a wooden chair, break off a pool que. A stick plus the kowledge in your head of how to use it, can be priceless. This also goes for short baton techniques. Any short stick will do. I understand a good London Bobby with his truchion is worth three normal people in a fight. For hiking, I like a shorter staff. The old rod, as in "Thy rod and staff comfort me." This is a short staff that comes only up to your lowest rib. I find it to be manoverable and handy.
A club was mans first weapon. The simple blunt instrument. A walking stick/hiking staff/boken is just a refinment of 50'000 years of evolution. The elegance of simplicity.
Short of a gun, I really don't think there is an equivent. Learn to use a stick right, get good instuction, and you have a tool/skills base that can never be taken from you, outlawed, or be not available. The nearest broom or floor mop can provide you with a defense tool.
Teddy Roosevelt had quoted an old Masaii proverb. "Speak softly and carry a big stick, and you will go far."