I spent the Fourth of July at Fenway Park where I saw the Red Sox beat the San Diego Padres 8-2 in an interleague contest.
Seated next to me was a gentleman by the name of Don Fields. Don is from Texas and bears a slight resemblance to knuckleballer R.A. Dickey (who is also from Texas). We had a very nice conversation throughout the game. It made the 90 degree plus heat far more bearable. Don told me that he and traveling companion from Florida have been to 28 out of 30 MLB parks this season with only Yankee Stadium and Rogers Centre in Toronto left on their itinerary. They make an interesting pair with his orange Astros cap and Vicki's Rays cap which both have pins from all the MLB teams they've seen attached to them.
Needless to say, this is something I have always wanted to do myself. Don told me that he has been keeping a blog about their journey. If you can't visit 30 ballparks during the course of a season, reading his blog is the next best thing.