Eric Slivka, MacRumors.com:
Microsoft’s market capitalization peaked on December 30, 1999, reaching an intraday high of $119.94 per share. With Microsoft having documented 5,160,024,593 outstanding shares as of October 31, 1999 in its quarterly earnings report, the company would have had a market capitalization of $618.89 billion on December 30.
Apple’s most recent quarterly filing listed 937,406,000 outstanding shares as of July 13, 2012, and with the company’s stock price hitting $660.73 today, its market capitalization reached $619.37 billion.
Even crazier, Apple is now worth over $200 billion more than its nearest competitor, Exxon Mobil, and almost $400 billion more than Microsoft. If you want to put a picture to this, check out the divergence of Apple and Microsoft over the past decade.