While most of the U.S. continues to endure sluggish or retreating housing prices and foreclosures still remain a persistent blight on the economic landscape, ultra high net worth individuals continue to fork over huge sums to garner real estate in most of the world's most exclusive enclaves.

While London and New York remain white-hot in terms of luxury home demand and prices, other international hot spots including Mumbia, Shanghai and Sao Paolo are closing the gap, according to "The Wealth Report: A Global Perspective Of Property and Wealth 2011" from Citi Private Bank and Knight Frank.

Among high net worth individuals, the report found that New York and London -- by virtue of their rarified status as true global commerce hubs -- will remain top destinations for primary and secondary residences in the next decade.

However, mainly as a reflection of the growing number of millionaires and billionaires in China, Japan and India, survey respondents cited Mumbai (up 118%), Shanghai (91%) and Sao Paolo (66%) as the most important and alluring cities for big-dollar real estate purchases.

In 2010, the collective wealth of high net worth individuals surged 22%, primarily as a result of the rebound in equity markets around the world. Worldwide, the total number of billionaires increased 140% last year.

By geographic region, the super rich in Asia now hold more than $11 trillion in assets, just a tad less than their counterparts in Europe and quickly gaining on North America, home to individuals worth more than $13 trillion.

Steven Wall, director of the Scorpio Partnership, in the report wrote that "China may eclipse the U.S. in billionaire numbers before Asia Pacific overtakes North America. That growth may be strengthened by the range of wealth sources driving economic growth."

The growing economic clout of emerging markets in Asia, South America and Eastern Europe helped propel luxury residential property around the globe. The report found that 40% of the world's most exclusive property markets increased in value in 2010 and six of the top 10 gainers were in Asia with Shanghai, up 21%, leading the pack.

On average, property represents 35% of the investment portfolios of ultra high net worth investors, so it's clear this upward trend in real estate prices will likely continue through the decade barring any dramatic geopolitical shakeups or natural disasters. Monaco and London still rank as the top two most expensive residential locations in the world.

Besides sunning themselves on the French Riviera or summering in the Hamptons, the super rich are increasingly assessing the quality of cities' school systems and their tax rates before forking over eight- or nine-figure checks for second homes. Twenty-nine percent of second-home buyers in Asia cited "education of children" as their main consideration.

But that's not say the wealthy aren't interested in the finer things, too.

The report said 64% of high net worth individuals will increase their spending on art, fine wines, yachts and private jets over the next five years as well as increase their donations to charities.