I would reply to this but my wrists were slapped for being insensitive for the last faux Ray Allen trade thread I did.
That being said to answer Celticswillwin43's question. I am not sure, but I know the Celtics acquired Danny Ainge from the Toronto Blue Jays and although it wasn't a trade it was a transaction between two sports. Also former Celtic Gene Conley is the only player to win championships for two professional sports team (the Milwaukee Braves being the other as a pitcher).
I can picture Ray Allen and Bill Belichick having much in common given their focus and determination.