About the choice of the half-elven, some of you should read what Tolkien has to say about it and see whom the choice was given and why. A few of you seem to be cloudy on your understanding of the matter.
http://www.barrowdowns.com/faq_halfelves.asp
Elwing, Earendil, Elros, Elrond, Elrohir, Elladan, and Arwen were given the choice.
Elwing, Earendil, and Elrond chose immortality.
Elros and Arwen chose mortality.
Tolkien never recorded the decisions of Elladan and Elrohir.
Elrond's children were given a choice because they had a renewed Elvish strain from their mother, Celebrian, daughter of Celeborn and Galadriel.
Elros' children lacked that Elvish strain. Subsequently, they were given no choice.
[ January 03, 2003: Message edited by: Legalos ]