Just read a very interesting article from Prospect Magazine:
http://www.prospect-magazine.co.uk/a...ls.php?id=8152
Basically it says that the reason humans and indeed other animals die of old age is that we have a sort of 'death program' that kicks in and shuts us down. It suggests that if we stop the gene that does this we could live to be very old, or at least be healthy and fully functioning a lot longer.
I once read somewhere some scientist saying that the first person that will live past 1,000 has already been born. I'm not sure this is true but how long do you think we will live given medical advances such as this (I'm in my 20's now).