I just got an email from MLB.com (I am somehow on their mailing list due to a sweepstakes I entered) and it said: "A base has been stolen in the 2008 MLB World Series, now America gets a free Taco. Run on down to any participating Taco Bell location between 2pm and 6pm on Tuesday, October 28, 2008 to get one free Crunchy Seasoned Beef Taco."
I do not really follow baseball, but I was glad to get this email about Taco Bell giving away a free taco to any American citizen!
It does say participating Taco Bell, so always check and make sure your local store is participating in this promotion.

The link for this promotion is here, and here.