With Bill Gates net worth at $56 billion, the aspiring rich are dreaming of billions as opposed to millions nowadays. It’s no longer who wants to be a millionaire, but who wants to be a billionaire. Today’s richest people measure their net worth in the thousands to tens of thousands of millions, and Bill Gates’s is leading the pack with more than fifty-thousand million dollars to his name. (Fifty thousand million dollars is the equivalent of 50 billion)

A billionaire is, according to wordnet.princeton.edu, "a very rich person whose material wealth is valued at more than a billion dollars ", or as wikipedia defines it, "A billionaire is a person who has a net worth of at least one billion units of currency, such as United States Dollars (USD), Pounds or Euros."

In 1986, Forbes’s billionaires list had only 140 known billionaires in the world. This year, the number of billionaires named in the Forbes list of the world’s billionaires was 976.

Top billionaires (reported by Forbes)

Click here to view the 2007 billionaires list