I AM an EX-Smoker...( i haven't had one for 19months)  and I am the first to admit ex-smokers are often the best at preaching (or worst as it may be).. but you know what I mean? The most forceful). I stive and hope I am not one of those, although I do encourage people who are struggling with giving up or even considering it.
I know from experience, people forcing their anti smoking opinions on you do more harm than good quite often. I can't tell you how often I saw a antismoking ad on TV and instanly went for my pack.
I had smoked for over 15 years and had a few decent attempts and several more half hearted attempts at giving up... but still the habit could not be kicked.
Then I gave up for no real particular reason and I found it so easy it made me wonder why I couldn't do it before... in the last 19 months I have had some hindsight and thought I could share it here and maybe encourage someone to stick it out, consider giving up, or just be supportive to someone you know who is struggling with it.

My number one rule in hind sight: You have to be ready and committed and true to YOURSELF. In all honesty, if you have to fight the habit with every inch of your existance every moment of the day, you are not ready to give up... and as soon as you let your guard down the first thing you are going to do is pick up a smoke. Stop trying, and come back and try again later, in a different mind set.

Well that was the only "RULE"... the rest is only personal experience and possibly can be taken as advice to try...

I changed my day to day habits. I had always smoked outside only, and never in the house. So I waited until the coldest point of winter, when it was uncomfortable to go outside with out deliberately rugging up, and promised myself I would only go outside if it was to play with the kids, hang out the washing or go somewhere.
Which led to my next promise... I promised myself to leave my smokes at home. And not smoke in public, I also added to this, not to smoke infront of the kids.
I didn't go cold turkey. I had in the past tried everything from cold turkey to gums, patches and even Zyban! This time I went back to the patches and promised myself to stick with the entire programme as specified in the leaflet that came in the box of patches. As I used to spend alot of time outside, reading the catalogues or watching the world go by in my "little spot" where I had an ashtray and a chair.... I moved the chair (I actually put the chair away in a shed) and ditched the ashtray. My smoking spot no longer existed. I tried to get in the habit of when ever I used to go for a smoke, I went in the opposite direction (inside and to the kids rooms) and played or read with them for 5 or 10 minutes instead. I drank heaps more water, and left a bottle of water where I used to leave my cigarettes.
Over the time it took to work thru the "patches program" I gradually had reset my habitual routine.... I also found myself spending a lot more time online, on auction sites listing stuff from around the house, getting involved in forums, which I had never done until that point, and generally distracting myself with being busy doing things that are not smoker friendly.
I found at the end of the patches program I had lost pretty much all the physical urges and also had not chemical cravings either..... and had done it with out really thinking hard about it....
I think when you get to the stage where you can say, "Hey, it's been 2 or 3 days since I even thought about having a smoke." It is a fair indication you are getting somewhere. But don't let your guard down there...keep deliberately forming new habits to replace the old one.

So what is your story? What made you read all this. Would you like to share? Please do!