Program yourself to hate smoking. Continue to smoke but try to be conscious of it. Feel the smoke while you inhale, try to think about what's happening to your gum, teeth, throat, lungs, hands etc. look at yourself in the mirror and notice the negative effects of smoking. If you're in a city that bans smoking indoors then feel sorry for yourself everytime you go out to have a ciggeratte, because this habit is controlling you and making you do things you won't necessarily do. Start thinking about how the not smokers have a better life and how they're better for not letting this happen to them. Eventually if you keep thinking like that, just negative things about smoking, you'll start hating it and naturally cutting down until you find the right moment to go cold turkey and then just do it.
Oh its easy. I've already quit 10 times. I'm actually thinking of quitting again next week :)
Actually the only time I managed to quit smoking for more than a few weeks when I was away from my friends/girlfriend for a five months and had no one smoking around me all day. It's easy for me to quit, it takes me a -pretty painless- couple of days. But after a while I relapse.
Hope that helps, it worked for me.