As a locksmith, I would come across graphite constantly. While indeed it does make a pretty good dry lubricant, refrain from being liberal with its use. A little goes a long way. CWL is also correct in that it wants to absorb moisture. I can't tell how many calls I would run into where someone had used some graphite, then later followed it up with some WD40 (UGH), creating a sticky, gloop situation, hence the request for a locksmith.
Teflon dry lubricants are great. Medeco used them for their locks all the time and I found it quite satisfying.