When is “Good” Good Enough for Bitcoin?

This morning, StumbleUpon brought me to this truly excellent post about solar cell efficiency over at the University of California, San Diego's Do the Math blog. Author TMurphy makes some excellent points and I'll leave it to you to read the entire post - it certainly deserves the attention - but the primary argument, the one thing the entire article boils down to is that, while research on more efficient solar energy is certainly worthwhile, what we have now is good enough and we should start focusing on cost rather than efficiency.