Paintbox
Firstly the very best of luck from someone else in a similar position. I posted this on Jetblast a few months ago
here and a number of people were very helpful,
BUT the bottom line is that it is down to pure will power.
One trick I use is to make sure that I always have my baccy, papers and lighter with me. I know that this flies in the face of conventional wisdom, but I find that being without the stress caused by knowing I can't have a fag helps me not to want one!