As well as all the fine observations/opinions/words of advice here...
-I'd hate the thought of having to do it, but...some of the times and places I shoot, if it came to it, it would make an available weapon for self defense
-it makes you look really cool :-) ...almost like you know what you're doing!!!
Yes, very good points. The weapon one had occurred to me too.
As for the other, I've noticed that if I'm out in public, then using a tripod (or a TLR, or a Cokin filter) then I've got a somewhat better than 50% chance of someone coming up to me, assuming I'm a pro photographer, and either asking for advice or asking me to take a picture of them on their camera.
Also, there are some areas (that seem to be public, but legally aren't) of Sydney where personal photography is permitted but professional photography is not, unless you have paid a license fee. It seems that most security peoples' operating definition of "professional photographer" is "someone using a tripod" - I've been stopped and questioned a few times.
Here in Seoul too I have had the displeasure of being haressed by some people in black suits and wires coming from their ears. However, this happened only in one very popular area and it happened everytime I unfolded my tripod. Other people were shooting their P&S to their heart's content but I was questione, they stopped me from doing anything until they completed their chit-chat on the walkie talkies and allowed me under supervision to complete my shoot..... for the phobia competition. No freedom as those who think they have freedom.
However, I carry my manfrotto everywhere and seldomly nowadays shoot without a tripod.
Since my last post in this topic, I've thought of an added disadvantage of using a tripod. In certain public/semi-public places, using a tripod causes the security people to treat you as a professional and ask you for your permit to shoot there. At a couple of places I've taken my tripod, I was told that if I was going back I should contact the appropriate authority first - charges would be waived as I'm "only" a recreational photographer, but I'd still need the magic piece of paper (or at least to have spoken to the right person) to avoid being hassled or asked to leave.