I took a great trip to Minnesota late this summer to visit the one year old Target Field. Its a great ballpark and a HUGE upgrade from the Metrodome. The Twins really paid alot of attention to little details which made nice park a great one.
This plaque, dedicated to the people of Minnesota, is located on the main entrance plaza. Its near the ticket windows to the right of the "Gate 29" entrance. As usual, the plaque lists the owners of the Twins, various local politicians that made financing possible and the designers and builders of the stadium. (I believe this is the first major league ballpark that uses the new Populous name. Citi Field's plaque lists "HOK Sport" as the architect.)
An interesting touch is the laser engraved image of Target Field itself. I've never seen something like that on a dedication plaque. The plaque seems to be made of regular sheet metal with all of the names/images engraved on it. Teams seem to be getting away from the heavy brass plaques that older parks had and are now going with ones of this type of metal and plastic like at Citi Field.
You can check out all of my photos from Target Field at StadiumPage.com.