I think quitting smoking has, in fact, affected my sleep pattern (for awhile there, I didn't appear to be experiencing any physical effects).  I've been waking up earlier in the A.M., and sometimes I can fall back asleep and sometimes I can't.  Or sometimes I do fall back asleep and then I wake up again 10 minutes later, and so on.  The funny thing is that when these disturbances occur, I feel wide awake for a few minutes, then I get tired.  Or, maybe it's the fact that it's 6am and I don't know what else I'd do besides just go back to sleep.  I don't know.  It's odd and it's not that it's really that disturbing, b/c anything that helps me get to work on time for a change is a good thing.  But hopefully it'll go away soon.  I've read that the physical effects of quitting smoking disappear altogether after 2 weeks.  I'm working on my second week right now, so hopefully the sleep will cease to be disturbed.