A lot of readers of this blog may also know about the webcomic called xkcd.com.
[If you have never read their comics go there now and don't stop until you have read them all. Make sure you read the mouse-over (place your mouse over the comic and a small text box will come up) It is usually funnier and compliments the comic strip.]
Anyhow, for those xkcd lovers and those who love sports will appreciate their second post on the new what-if blog. The question is What would happen if you tried to hit a baseball pitched at 90% the speed of light? For the long answer go there. For the short answer, the batter would advance to first and be considered "hit by pitch".