Last night the PBS show "Nova" had what was a parallel to this thread and its predecessor on "Time" (and pondering traveling forward and backward through it). Although no concrete conclusion was offered (aside from serious doubts about traveling backward being raised), this tid-bit 'forced' me to revive this thread.

I'm paraphrasing Steven Hawking...

"I won't bet money against time travel with anyone because they may have been to the future... and know better".