For those of you who haven't heard this: Last Jorge Posada hit an infield pop-up to 3rd base. As A-Rod rounded 3rd he shouted "mine" at the Blue Jay's 3rd baseman, and he missed the ball. For those of you who dont play baseball this is one of the most childish and immature things you can do.
here's the story:
http://mlb.mlb.com/news/article.jsp?ymd=20070531&content_id=1996569&vkey=news_nyy&fext=.jsp&c_id=nyy