Disclaimer -- I am NOT an Intellectual Property or Privacy Rights attorney (but I did stay at a Holiday Inn Express last night) -- but I have studied this issue for my company and for my own personal interest.
Some general comments -- Each jurisidiction has its own rules -- so just because something is permitted in California does not necessarily mean it is permitted in Oregon.
While people talk about how using a photograph of someone is OK for news editorial purposes but not for commercial purposes, the line is not that clear.
Last, the legality of the useage can depend in large part on the purpose of the image. For example, did you put Tiger Woods in your poster so that people would buy it because it was a picture of Tiger Woods or was TW in the poster because he was a Masters Winner and it was a poster of Masters' Winners? (That is from a real case and TW lost.)
Privacy rights, copyrights, etc. are fraught with legal issues -- photographer beware!