That's interesting about the icelandic volcano - I'm not sure I have the expertise or fortitude to invest based on geological phenomenon.
IMHO the real-estate bubble is of astronomical proportions. There have not only been cranes everywhere for the past 7 years or so, but the prices of housing have climbed and climbed much faster than wages. College grads can hardly afford to live in the cities they work in, and wealthy folk often own several apartments, but don't rent them all. Driving in Shanghai, you can see a lot of dark apartments at night. I was in Beihai, and toured an apartment site that was basically being built in a field. Many new complexes have very low occupancy rates. I've had a sense that this was building for a while, however, there are three things that I found different this time: 1) People were complaining about it. Friends and taxi drivers were complaining about the outrageous cost of housing and other goods. 2) There were phone numbers everywhere in windows and on walls like graffitti advertising to sell new apartments. Tons of phone numbers everwhere. 3) There is a very large number of outfits, little store fronts that are filled with a handful of people, some blueprints, and computers. They all sell property, much of which that has not been completed. There were tons of these little shops. I didn't see nearly so many of these a couple of years before. My hypothesis is that local governments keep lending for building because they get kickbacks, and because the construction increases GDP. Of course, they haven't done this by borrowing, but by speculation. When China moves, they all move. It's just a way things go there. That said, I don't understand China enough to think I can call the timing on this correction, or even know what it will look like. (I am guessing that the one-party system won't survive). I do know that what goes up must come down, and real estate in China has climbed sky high. I won't short China, but there is no way that I would invest there either.
The problem is any shift in Chinese attitudes will be passing through the filter of the Chinese state, so any attempts to think of it in a fully Western way is going to be peril-fraught.
The best money I've ever made, and the most comfort I've ever had, was "betting against the USA." In December 2004 I took my retirement fund out of bonds and threw it all at emerging markets funds, FOREX funds and every other aggregate measure I could find that basically said "foreign economies are going to grow faster than the US economy." It was partly luck (my knowledge of the world is imperfect) and partly skill (my knowledge of geopolitic is greater than my knowledge of individual companies' performance) and it paid off about 70% over three years. In September 2007 I took my retirement funds out of emerging markets and forex because I no longer felt that anyone could predict the general direction of the market; the research I had been doing predicted the collapse of the housing bubble but not much else. I responded by putting my money in a ratcheting index fund, so when the S&P dropped a month later I didn't lose a dime. It's still there. It's safe to say that I'm much more interested in "not losing money" than I am in "making money" which I recognize as an excessively-conservative policy for a 37-year-old. However, I just don't trust any system in which public opinion trumps data.
I do enjoy making small investments like my aforementioned short on gold -but even that was only 1k which is really just a way to put my money where my mouth is. I suspect I'll make a similar bet on china, but we'll see. Most of my non-401k assets are still sitting in interest bearing accounts, but I've been nervous to actually invest them - it's hard to gauge which way the market is right now.
Now I want to build a chicken tractor that has very slow solar powered wheels. It would be fantastic if you could program it to drive, back and forth, back and forth, over a large stretch of lawn. Maybe moving a couple of feet per day.