Not quite sure about the lyrics to one of your favorite songs? Planning to look them up on the Internet? Better look fast. The U.S. Music Publishers Association says it is going to pursue legal action against Web sites that post lyrics and song scores. The MPA, which represents sheet music publishers, says it isn't just looking to shut the sites down or even reap monetary rewards. MPA president Lauren Keiser says that throwing some people in jail would make their campaign even more effective.