The Multiverse - pro and con
I love this kinda speculation.
I highly recommend the recent issue of SciAm with articles on multiple universes.
I love the thought that there's an exact copy of me every 10 to the 10 to the 28th power LY away, siting there pissing off folks in his own corner of the multiverse.* And orthogonally, my infinite numner of quantum twins forking off every picosecond.
-p
* this HAS to be so if the universe is 'infinite'. Why because the combinations and permutations of all matter run out and gotta repeat. Just gotta.