FILE - This Oct. 4, 2011 file photo, shows the Apple logo during an announcement at Apple headquarters in Cupertino, Calif. Apple's market capitalization topped $500 billion in opening trading ... more 
FILE - This Oct. 4, 2011 file photo, shows the Apple logo during an announcement at Apple headquarters in Cupertino, Calif. Apple's market capitalization topped $500 billion in opening trading Wednesday, Feb. 29, 2012, climbing to a mountain peak where few companies have ventured and none have stayed for long. (AP Photo/Paul Sakuma, File) less 
1 / 25
Associated Press | Photo By Paul Sakuma, File
Wed, Feb 29, 2012 1:30 PM EST