Frodo at the end of the movie (spoilers)

[The Leper Fairy]

Maybe I missed this somewhere but why did Frodo leave with the Elvs at the end...? I thought he left because he couldn't be content in the Shire anymore. My parents say it's because he posessed the ring... which I don't think is right because Sam also had it for a short time.

So what's the real reason?

[I'm Murrin]

It was because of the ring. Ringbearers will suffer the rest of their over-extended lives, feeling the thinning-out that Bilbo felt, and Frodo especially was affected by his wounds from the wraith-blade and from Shelob (it probably wasn't mentioned in the film, but he stayed a while before leaving and on the anniversary of each injury the illness returned in part). To recover from this, the ringbearers are taken with the elves.
I believe it is mentioned that if Sam begins to feel the effects of his short ownership of the ring, he would have the opportunity also.

[The Leper Fairy]

Ah, Thanks Murrin!

[Seafoam Understone]

I just got back from my second viewing of ROTK (still awesome) and there were clues given that Murrin pointed out and the way I saw it was that Frodo after being subjected to the ring and his journey and his last temptation to KEEP the ring for himself instead of destroying it affected him deeply.
In the film it shows Frodo loitering about in Bag End because of his restlessness. He too misses the ring like Bilbo did (and same with Gollum/Smegol) there was some dialouge that I missed (have to wait for the captioned version of the film) but I'm sure Frodo gives insight to what was going on inside him.

Sam had it but briefly. He also was very distracted by his need to find Frodo again. Yes, he held it back when offering to return it to Frodo in the tower but me thinks Sam was made of even sterner stuff than any of the Hobbits.

Samwise Gamgee is still one of my favorite heroes and ironically that's a lot for a "secondary" character.

[MsMary]

The story was passed on among Sam's descendants that Sam also went to the Grey Havens, and went oversea, partly because he was also a Ringbearer, albeit for a short time, and partly because of his love for Frodo.

~MsMary~

[duchess of malfi]

I believe in the appendixes at the back of the book it does say, as MsMary said, that Sam also goes across the sea, after the death of his beloved wife. The restlessness did not hit him until then...

The elves gave this opportunity to all three of the hobbits who were Ringbearers, in part to honor them, and also for their healing...

[Worm of Despite]

Sam was one-hundred and two years old when he arrived at Tower Hills. There, the last person to see him was his first daughter, Elanor, and it was to her he left the Red Book. It's said that he passed the Towers and went to the Havens, where he left Middle-Earth for Aman--to Valinor and to Frodo.

But I fear that by the time Sam got to Aman, Frodo was already dead. Maybe I'm wrong there, but remember what Saruman said to Frodo in the book:

"But do not expect me to wish you health and long life. You will have neither. But that is not my doing. I merely foretell."

[memla]

I don't like Saruman. He was mean. And wrong. Frodo and Sam (and Gimli) were given the grace to travel to the undying lands.

They were given the grace of immortality.

Saruman could not and did not see this. He would have been right if Frodo had remained in Middle Earth. I'm glad Frodo was allowed to travel to the Blessed Realm. I like Frodo.

[Xar]

I disagree with the immortality issue... Tolkien himself, in a letter of his, #325 ( to Roger Lancelyn Green, July 17, 1971 ) explains that Frodo and all other mortal beings could only live in Aman for a certain period of time, because the Valar had neither the power nor the right to confer immortality. They would therefore live the rest of their lives in the Blessed Realm, slowly healing from their cares, their unhealable wounds and so on, and then die willingly ( much like Aragorn did ).

As for Sam, though, he did apparently leave for the Blessed Realm too, when he was old and Rosie dead... yes, as MsMary and others say, Sam was given this grace because he was a Ringbearer too, although just for a bit. Frodo himself says this in the last chapter, "The Gray Havens", when he says goodbye to Sam.

My personal belief is that Bilbo probably just spent a handful of years at most in Aman, before passing on; but Frodo probably waited for Sam, before going - after all, he knew Sam would someday come. When Sam reached Aman, only then - perhaps a few years later - he and Frodo died.

I don't think Saruman's foretelling could reach the shores of Aman - Saruman merely saw Frodo's unhealed wounds and his sense of no longer belonging to the Shire, and hence the lack of "health" and "long life"; Frodo would vanish from Saruman's view the moment he would set his foot on the elven ships, so probably Saruman mistakenly believed that would mean Frodo's death. Saruman was cut off from the West when Gandalf shattered his staff and cast him out, although he was "unofficially" banished ever since Gandalf's death and return; nevertheless, I believe that once he was banished from the Blessed Realm, he would not be able to return to it or see it any longer - therefore not being able to see what would happen to Frodo once he would leave Middle-Earth.

[Variol Farseer]

Remember also how time seemed to pass slowly in Lórien. As Sam said to Frodo:

'Well, I can remember three nights there for certain, and I seem to remember several more, but I would take my oath it was never a month. Anyone would think that time did not count in there!'

'And perhaps that was the way of it,' said Frodo. 'In that land, maybe, we were in a time that has elsewhere long gone by.'

- The Fellowship of the Ring, book II, chapter 9, 'The Great River'

In Lórien, Galadriel used the power of her Ring to try to create a miniature replica of the Undying Lands. It seems reasonable to guess that time would also seem to pass more slowly in Valinor and Tol Eressëa, where Bilbo and Frodo went. Perhaps for them only a few years seemed to go by while Sam grew old in Middle-earth, and not only Frodo but Bilbo may have been alive when Sam came to join them.