Multiple HDTVs on one box?

I currently have a HD cable box connected to a HDTV.  I am thinking of getting a second HDTV for another level of my townhome.  Is there any way to run two HDTVs from one HD box?  Based on other posts I'm guessing that I can't do that until (if) Cox goes to wireless boxes.  So will I need a second box?  And if so, is there a multiple box discount for loyal long-term customers like myself?  :-)