I know that the package sympolizes the hope for Tom Hank's character to not give up and to give him a "mission": to survive and deliver the package.
But I read somewhere (in a behind the scene interview, or a trivia), that the package contained a celluar-powered, water-proof, satellite phone.
In the movie, we don't see the package delivered (in hand) to its destination, and thus we get no closure on the content of the package.
Was there any hint that it might have contained such an item?
The satellite phone info comes from a 2003 Superbowl commercial parody:
A FedEx commercial during the 2003 Super Bowl parodied the final scene of the film, in which Chuck returns a package to its sender. In this version, the woman answers the door, and when Chuck asks what was in the box, the woman replies: "Just a satellite phone, GPS locator, fishing rod, water purifier, and some seeds. Just silly stuff."
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In fact the third draft of Cast Away (that has a few differences from the finished movie) reveals that the package contained two bottles of salsa verde:
The package, however, is exactly the same as in the finished movie: the same angel wings, the same woman at the beginning, and the same insane resolution to deliver it no matter what. And then, on his 1,000th day on the island, Chuck goes "eh, what the hell" and opens the box. So what's inside?
Two bottles of salsa verde. Also, a note from a woman named Bettina begging her husband to come back, apparently hoping some spicy condiments will do the trick. Chuck looks at the bottles, reads the note, then puts everything back into the package and continues carrying it with him. It makes absolutely no difference. This could've perfectly been a deleted scene in the movie itself.
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I always thought it was divorce paperwork. And (at least in the version that was presented) there's no way it was bottles of salsa, that package is shaped to hold documents and wouldn't be the proper size for bottles of salsa.
Ultimately, the question is moot. If you spend too much time thinking about what's in the box, you missed the point of the box.
