Much of the current world food crisis and skyrocketing grocery bills have their roots in the deregulation of US commodity markets over the past 15 years. Without these controls, speculators in the stock market can cause artificial food price spikes and shortages while they try to turn a profit. New financial reform laws such as the Dodd-Frank Wall Street Reform and Consumer Protection Act seek to end such volotile speculation, but are at risk of being watered down before their implementation. Write a comment to the CFTC today to support reform and stop Wall Street from gambling on hunger.
You can also check with the financial managers of your pensions/401ks, organizational endowments, etc. to make sure that your money is not invested in commodity derivatives. It has become en vouge to do so, so there is a decent chance that your money may be contributing to the problem.