http://www.greaterthings.com/JJDewey/Eternal_Lives/

This man makes a good case for reincarnation/multiple mortal probations in this article - all backed by LDS scripture and quotes from church leaders. It's a long read, but VERY informative and although there's a lot of his own conjecture, it's sourced pretty well and his conclusions rang true to me.

I am also reading the Amalgamated King Follett Discourse given by Joseph Smith, and he discusses some pretty interesting related things there.

One thing I want to add that was not mentioned in the article above - the church teaches that those who have lost their children to death before the age of accountability will have the opportunity to raise them to adulthood during the millennium. Is this not essentially reincarnation?

I'd like to read the book "Teachings of the Doctrine of Eternal Lives" ( http://www.amazon.com/Teachings-Doctrine-Eternal-Lives-Anony mous/dp/1934537969). The entire book is simply quotes about the topic by LDS leaders, and scripture quotes.