Agreed, when I had quit (both times), I used my hobbies to keep myself occupied.
Body Work/Painting were the best, because you can't smoke and wear a mask/fresh air respirator setup at the same time :D Same goes for building engines, you can't smoke, might get ashes inside that rebuilt engine. :D
My advice to anyone who is going to quit, avoid hobbies that give you ample time to sit or hobbies that give you a chance to have a free hand. If you can sit or have a hand free, you can smoke.
Avoid Instruments too... Cause every rocker knows it's possible to play a screamin' guitar solo, give the finger to someone in the crowd, slide your sunglasses back up your nose, and smoke a cigarette all at the same time. :D Ok I'm joking (though it can be done), an instrument is a great way to keep your mind and body occupied.
Sadly, in this day and age, it's nowhere near as "occupying" to learn an instrument (what with video games like Rocksmith and such out there). When I learned to play guitar I had no idea what I was doing, I had a couple tabs for some songs and just kept goofing around with the guitar until I figured out what needed to be done and taught myself how to play.