I think a big reason people are more focused on Facebook Apps (and consumer web apps in general) to the exclusion of more pressing world problems is because tho

I think a big reason people are more focused on Facebook Apps (and consumer web apps in general) to the exclusion of more pressing world problems is because those problems are hard. I think it's well understood that one of the driving forces behind the boom in internet software entrepreneurship is that the barriers to entry are extremely low- historically low compared to other developing fields. For most of the readership of this board, "barrier to entry" does not just mean financial resources but also domain knowledge. I would find it enormously rewarding to work on many of the "grand challenges" listed here, but I lack the basic science background to do so. Maybe if I had been a physicist or a bioengineer and picked up hacking on the side. I may be able to find a scientist to collaborate with, but I would still be a little out of my depth, and they certainly don't hang out at the same startup gatherings. Or am I being too defeatist? Does anyone have success picking up biotech or solar cell design or neuroscience on your own, like some people pick up programming or sales on their own? What resources would help you do so?