When I was seven and my brother was eight, we both wrote to 'Where in the World is Carmen Sandiego?' for a free t-shirt. Two weeks later his arrived in the mail, signed by Carmen Sandiego herself, accompanied by an autographed picture of the cast, an official membership to the 'Gumshoe Club,' and a Rockapella casette tape. I got a postcard.
It's ten minutes from Indiana.