CEOWORLD Magazine recently released the CEOWORLD Magazine 250 list for 2011. The software giant, Microsoft Corporation (MSFT) topped the CEOWORLD Magazine 250 list, followed by five oil giants, Exxon Mobil Corporation (XOM), PetroChina Company Limited (PTR), Royal Dutch Shell plc (RDS.A), Petroleo Brasileiro SA (PBR), BHP Billiton plc (BBL) and International Business Machines Corp. (IBM). [...]