LM Otero / AP
This Oct. 26, 2006, file photo shows an Exxon logo seen at a Dallas gas station. Exxon has once again surpassed Apple as the world's most valuable company after the iPhone and iPad maker saw its stock price falter, according to reports Friday, Jan. 25, 2013. Apple first surpassed Exxon in the summer of 2011. The two companies traded places through that fall, until Apple surpassed Exxon for good in early 2012.