Not really. No tiny island in the tropics. No Fed-Ex packages. No long lost girlfriend. But the feel of the two movies is the same. Both are stories about a guy, an ordinary sort of guy. Smart, talented, employed. Not saintly or evil. I'd say, "Everyman," but I don't think "everyman" is what Tom Hanks is aiming for precisely. This guy, whoever he is, isn't supposed to represent all average, ordinary people. He is an idiosyncratic individual trying to get by in his own life.
Anyway, this ordinary individual undergoes an experience. In That Thing You Do! he's the Tom Everett Scott character, a Tom Hanks look-a-like (it's really disconcerting; he looks like a clone of Tom Hanks from Big) who takes the whole "popular boy's band" adventure in stride. The event is seen from his eyes; the experience he gains isn't negative or positive, it's just life. He gets the girl, but in an ordinary, well-yes-of-course kind of way.
Castaway, with Tom Hanks in the starring role, is very similar. The ordinary hero doesn't get the girl, but he does survive. Life unfolds around him until he is left, at the end of the movie, at a crossroads in open country. There's no huge thundering moment of climax. It's more that here, now, is another set of choices. Life will keep going.
This similarity of theme might seem like a fluke but both The Terminal and Catch Me If You Can, where Tom Hanks plays the main role and a supporting role, are the same kind of thing. The ordinary man of The Terminal is a good guy caught in a horrible situation (the scene where Viktor sees his country collapsing on T.V. but can't communicate his distress to anyone is the most haunting part of the movie). Viktor is heroic precisely because he is ordinary. He is good but not perfect. He is simple but not simple-minded. He follows the rules, but he isn't trying to make any kind of statement or win any kind of political battle. This is not Mr. Smith Goes to Washington. In the end, the secret (I'm giving away a lot of endings here) isn't the cure to cancer. Viktor is only trying to carry out a father's rather small but important wish.
Catch Me If You Can is somewhat different, but what I like about Hanks in this movie is that he doesn't play the FBI man as wrong or right. I guess that is what I find so amazing about Hanks. He has this capacity to play people rather than states of mind or political opinions. Which is why he could play the romantic hero on You've Got Mail (yes, my favorite Tom Hanks' movie) without making him snotty or self-pitying or apologetic. (And yet very, very funny.)
On an end note, Hanks is turning out something like five movies this year. Talk about being in demand!