"As soon as it is possible to do so, several North American companies are likely to move quickly to enter Cuba, the greatest untapped opportunity remaining in the western hemisphere," says Jim Powell.

Here, the editor of Global Changes & Opportunities looks at what he believes are the best investment opportunities for investing in Cuba, should such a change occur.

"In August, Raul Castro announced that 500,000 public workers in Cuba will be laid off and will need to find jobs in newly-legalized small private enterprises.

MOST NOTEWORTHY: BigBand Networks, Chipotle Mexican Grill, Vertex Pharmaceuticals and Cognos were today's noteworthy downgrades:

• BigBand Networks Inc. (NASDAQ: BBND) was downgraded to Hold from Buy at Jefferies and to Market Perform from Outperform at Morgan Keegan on the company's negative Q2 pre-announcement to reflect decreased visibility.
  
• Citigroup downgraded Chipotle Mexican Grill Inc. (NYSE: CMG) to Hold from Buy on valuation.
  
• Vertex Pharmaceuticals Inc. (NASDAQ: VRTX) was downgraded to Neutral from Buy at Merrill Lynch, as they believe investor expectations are high into November's American Association for the Study of Liver Diseases meeting.
  
• Soleil downgraded Cognos Inc. (NASDAQ: COGN) to Hold from Buy as they believe the strong Canadian dollar will depress operating margins and limit share upside.

OTHER DOWNGRADES:

• Jefferies downgraded Spectra Energy Corp. (NYSE: SE) to Hold from Buy.
  
• Goldman downgraded MeadWestvaco Corp. (NYSE: MWV) to Neutral from Buy and removed Crown Holdings Inc. (NYSE: CCK) from its Americas Conviction Buy List.
  
• UBS downgraded Atlantic Tele-Network Inc. (NASDAQ: ATNI) to Neutral from Buy.