My informed but ultimately presumably inaccurate guess is: if I buy about a million or so high end GPUs, and a few hundred petabytes of hard drives, I am somewhere in the ballpark of a human brain.
Given Moores law, that number is going to diminish. Given more knowledge about neurology valuable reductions in simulation complexity will be possible; you probably won't need a chromodynamics simulation to accurately replicate personality, the thermal noise in our brainware is far too great to depend on that kind of accuracy.
But yes, a human interpreter is ultimately possible because human minds are neuron actvity and neuron activity is physics and physics are as far as we know, turing computable.
That's what I think, too.
Either way, what I'm trying to argue against is the "you are an organism" thing. Not "everything within my skin" is necessary to run the program, I mean surely not the colon or metatarsal bones? To me it makes little more sense to call the entire body "me" than my car. Either way it's a vehicle, even if at the present state of technology I'm kind of stuck with this one.
I suspect that when we, in a hurry to signal allegiance to reductionism and materialism, tell people things like "you are an organ...
Here is a 2-hour slide presentation I made for college students and teens:
You Are A Brain
It's an introduction to realist thinking, a tour of all the good stuff people don't realize until they include a node for their brain's map in their brain's map. All the concepts come from Eliezer's posts on Overcoming Bias.
I presented this to my old youth group while staffing one of their events. In addition to the slide show, I had a browser with various optical illusions open in tabs, and I brought in a bunch of lemons and miracle fruit tablets. They had a good time and stayed engaged.
I hope the slides will be of use to others trying to promote the public understanding of rationality.
Note: When you view the presentation, make sure you can see the speaker notes. They capture the gist of what I was saying while I was showing each slide.
Added 6 years later: I finally made a video of myself presenting this, except this time it was an adult audience. See this discussion post.