I personally really disliked the fact that Clear Channel decided to put up a billboard ad that counted down to Ray Lewis' retirement. If you are superstitious, you could consider it a jinx, but for the most part, it isn't very classy and it gives the other team bulletin board material.
In any case, according to Boston.com, Ray Lewis happened to see it before the game and used it as motivation to win:
In an on-field interview following Baltimore's 28-13 win over the Patriots in Sunday's AFC Championship Game, Ravens linebacker Ray Lewis said he was motivated by a Massachusetts billboard counting down the hours to his "retirement party." Lewis said before the playoffs that this postseason would be his last.
“I was hurt when I saw a sign that actually said my retirement would [start] tonight,” Lewis said. “Man can’t dictate that. God dictates that.”
At least Clear Channel, who owns and operates the board, admitted to their mistake after the game by putting up this billboard with an egg on their face. I hope they refrain from this type of billboard in the future though.