Wow, lots of replies! Forgive me for not replying, I got lost
Katzpur: I'm not sure my sentiments now will be the same as when I posted, as I've recently done a-lot of thinking, but...
1) I believe my spirit becomes part of the spirit world - a universe that is the realm of the Holy Spirit, that interconnects all things. It is basically spiritual heaven and hell, depending upon what sort of life you have lead and your attitude to God. The exact form this world is, is in my view a mix of the phsical and the spiritual - one can be a spirit or have some semblance of physical form. It is during this period that the majority of people will, I hope, repent and reconcile themselves with God.
2) Yep. The last judgement, when the world is ended. It's when we will get our real (perfected) physical forms back - the total fusion of heaven and hell, and when God will become physically inescapable - no illusion of seperation between man and God will continue to exist.
3) Not twice, but twenty times twenty times
We will be "judged" immediately upon death, when we become aware of God's nature, and when/if we repent, we will join his side. At the last judgement, all those who have repented and reconciled with God become part of the kingdom, while the rest become tormented by it's fulfillment and the guilt of their unrighteousness in the ever-presence of God. Even here, after time has ended, they will be able to repent. Whether they will or not, is quite another matter.
I've never thought about it to be honest. As long as you avoid a belief in transmigration of souls (or their preexistence) then it sounds like we would consider any such belief a theologoumenon: a personal belief which is consistent with/not in opposition to the faith but is not part of official teaching.
Souls
definately are not preexistent - we (can) partly share in God's nature through Jesus' death upon the cross which returns us to being the image of God, but we do not partake of his eternal, atemporal nature. I don't think they transmigrate, but I can't discount any link between the ages - I felt some very strange things when I went to Rome and Pompeii, and there were just too many coincidences, for me to discount some form of link between myself and figures in the past.
Interestingly though, I recently read something in Matthew that seems to indicate some form of link between kindred souls - Jesus referred to John the Baptist as Elijah in Matthew 17:10-13
And His disciples asked Him, saying "Why then do the scribes say that Elijah must come first?" Jesus answered and said to them, "Indeed, Elijah is coming first and will restore all things. But I say to you that Elijah has come already, and they did not know him but did to him whatever they wished. Likewise the Son of Man is also about to suffer at their hands." Then the disciples understood that He spoke to them of John the Baptist.
Interesting no? I don't think it's enough to go all in for transmigration, but it is definate evidence of links between the prophets at least.