now that years have gone by and whatnot, i think this is even a bit more interesting.
Some time around 2009 Google CEO estimates 500 million terabytes of data attributed to the internet.
So by now, we could probably use a 2^64 computer to hold 2.x backups of the internet =P Which could have it's uses =P
as goes 2^128 and this idea
"Clearly you can't do better than (or even as well as) harnessing the largest set of good quantum numbers of every particle in the universe. (Your computer has to be in the universe!) "
Well there are ways to take a few values (say 8 for example) and based on these achieve further resolution than 8 (say 256 for example =P) Really there are many techniques which provide more resolution for processing and storage than their components, so I think identifying the whole universe may not be so impossible really.
I also think of the whole,... leaf in a pond thing. There's an idea that if you can *fully* define and understand one particle on the leaf then you can access the info of the entire pond. Perhaps with 2^128 we could define one proton so well that everything else is just implied lol.