Richest People of the World in 2011 as per Forbes.com :

The top 20 names of world’s richest people, in year 2009 as per Forbes.com, their occupation and the Nett worth that they hold are:

S.No     Name                            Nett Worth (in $ Billion)     Source of Income

1           Carlos Slim Helu 53.5                                     Telecom
2           Bill Gates 53                                        Microsoft
3           Warren Buffett 47                                        Investments
4           Mukesh Ambani 29                                        Petrochemical, Oil and Gas
5           Lakshmi Mittal 28.7                                      Steel
6           Lawrence Ellison 28                                         Oracle
7           Bernard Arnault                   27.5                                      Luxury Goods
8           Eike Batista                          27                                         Mining, Oil
9           Amancio Ortega                  25                                         Fashion, Retail
10         Karl Albrecht                        23.5                                     Supermarkets
11         Ingvar Kamprad

and Family                          23                                          IKEA
12         Christy Walton

and Family                          22.5                                     Wal-Mart
13         Stefan Persson                  22.4                                     H & M
14          Li Ka-shing                        21                                         Diversified
15         Jim C. Walton                     20.7                                      Wal-Mart
16         Alice Walton                        20.6                                      Wal-Mart
17         Liliane Bettencourt            20                                          L’Oreal
18         S. Robson Walton             19.8                                       Wal-Mart
19         Prince Alwaleed
bin Talal Alsaud                19.4                                        Diversified
20         David Thomson

and Family                         19                                           Thomson Reuters