i know anecdotal evidence doesn't amount to much but since this is the current topic of discussion i figure what the hell:
i quit smoking cold turkey on the 14th, about a week and a half ago. i didn't cut down at all in advance, smoked consistently right up until the hour i had to quit.
at first i just felt like having a smoke, like little things that usually prompt me to smoke would remind me that i couldn't smoke, and it was slightly annoying but easy to get over by occupying my mind with something else.
by the 2nd/3rd day i couldn't sleep and spent all night taking robotussin (i was sick) and watching richard dawkins documentaries on youtube. that's about when i started to feel strong physical cravings, like i had a knot in my stomach or like the feeling of terror you feel in the pit of your stomach if someone were to be holding a knife to you.
it basically just makes you feel like punching somebody.
but shortly afterwards these physical cravings subsided and its back to a mental battle of trying to forget all the little things that remind you to smoke. as of now i have successfully fought off the temptations though it still seems to be affecting my sleep. i've had 3 different dreams about smoking in the last 2 nights.
about two years ago, i used to smoke weed daily and had to abruptly quit one day in the same manner, and i have to say that i never felt any strong craving for weed.
i know what it's like to be around the stuff and try not to smoke, which is hard, but as soon as i removed myself from that element (moved a couple states away) it wasn't so bad.
although the funny part is that i never smoked cigarettes until i had to quit smoking weed and just felt like having something in my hand to smoke, so i guess i just traded addictions (though i wouldn't say it was a fair trade, kind of a rip off)