hold stocks in us companys that pay dividends long positions are exempt from capitol gains tax for a time... but a better idea look at the third world for skills you can use such as recycling alluminum or other soft metals into useable products as you will be able to make more money doing this then just scrapping em for quick cash, and with the net you can expand your customer base making this a bit more viable. just look into what your using for what lead is bad for plates and eat ware after all.

edit if that dont appeal then hoard seed's and learn to grow a few simple things like tommatoes or potatoes if the economy goes depression food and water will be a priemium item you can sell for a sum. as for drinking water a solar still or boiling it and collecting the vapor can produce drinkable water.