I did it for 15-years and now I've gone a week without it, so yes, you can do it. I think it's all mental. If you read all the stuff on here about what is happening to your body right now then you'll be able to fight off the urges.
For me, the three days were the worst. I kept going about life as usual, but I was in a fog and couldn't really concentrate. Staying busy, trying to stick to my routine, and going to the gym seemed to help. On the fourth day I was still somewhat in a fog, but I could tell it was lifting. By day five I felt great - not only physically, but mentally, because I knew I had just cleared a big hurdle.
Now it's just a matter of one day at a time, posting on here each morning and vowing to stay quit each day. I consider the 'triggers' like demons - and for me it's better to go after the demons head-on, rather than to avoid them. I had a few beers over the weekend while playing Madden on the PS3 - two things that always had dip associated with them in the past. I made it through that night without any problems at all (chewed gum instead of TimberWolf.) Small victories like that feel great and make me realize that I can do this. Not to mention that there's been no link between chewing gum and cancer.