Sphere, what a copout
In the book, Norman learns how to control the power, so the choice is a lot more difficult. Also, they don't just forget, everyone forgets, not just the three of them. The Navy is in on it too.
And for the guy that said Contact, what were you expecting? I though it was a great ending written by a scientist that had a lot of experience dealing with the government. Sagan was a big proponent of sharing discoveries with the masses, much like Ellie was in the movie. Of something like that happened, and the government saw an opportunity to take control of it and take it away from the people, don't you think they would?