Interesting idea, but not much fun living as a brain in a jar. I haven't got the best body in the world, but I'm quite attached to it. Also, forgive me for being overly negative, but whilst I believe there are ways to extend lifespans, afterall that's what medicines do, and there's some pretty exciting work with telomeres in c.elegans - live forever just sounds too good to be true - like 'get rich quick' - it'll never happen. Every generation has their own potion, lotion, idea for eternal youth, an elixir of life, but unless you are about to celebrate your 250th birthday, all 'live forever' ideas are doomed to failure. I would love to be proved wrong and eagerly await that time.