Governments around the world are targeting substantial amounts of funds for infrastructure improvements. It's a way to get people back to work and at the same time, restore and modernize essential networks. Projects receiving funds range from roads, bridges and tunnels to utilities and even broadband networks. The U.S. plan alone calls for public works expansion that compares with the great highway building projects of the 1950s.

More than $700 billion in the next two year has been allocated to infrastructure spending. "For investors who see weak corporate profits and declining stock values everywhere they look, global stimulus spending on infrastructure could offer some important and compelling opportunities," says Andrew Obin, Machinery and Engineering & Construction Analyst at Bank of America Global Research.

Obin points to a number of sectors - not just the construction industry but also building materials, industrial equipment and metals sectors - that may benefit from stimulus plans. "Investments in energy and utilities could see at least an indirect advantage from government spending, while companies that are involved with basic materials, heavy equipment, engineering, construction and broadband communications may benefit more directly. For investors seeking wider exposure to opportunities in this area, several mutual funds now focus solely on infrastructure, as do a small but growing number of exchange-traded funds (ETFs)."

In numerous countries, it has become clear that there is a tremendous need to invest in basic systems. In its most recent report card this year on the state of U.S. infrastructure, the American Society of Civil Engineers gave a D average to the country's dams, drinking water, energy and wastewater systems.

While there is great potential in infrastructure investing, don't expect a quick boost to your portfolio."Investors should not expect immediate returns from infrastructure investments; they may need to be patient," says Riccardo Barbieri, International Economist in London with Bank of America Global Research. One reason is that governments hold the purse strings and it will take time before funds reach infrastructure companies. Stimulus packages in some countries may require that contracts go to local suppliers or government-owned companies, which could limit participation by outside investors.