Apple has US$15.4B in cash. One has to start wondering what Apple will do with it, according to Fortune on Friday. Apple has made some small aquisitions on the past, however, that $15B could buy a lot.

Unlike some of the other big technology companies, like Microsoft, Apple doesnit pay dividends on its stock. So the money just keeps accumulating.

One clue would be to look at history. Apple has purchased some smaller companies to buy its way into key technology markets: PowerSchool for education and Emagic, a video effects company. Some of those acquisitions have not paid off, and Apple sold PowerSchool last year.

Another option is to buy back stock, but Apple has only set aside US$500M for that and spent only $217M of it, a small fraction of its cash. An often overlooked project is Appleis consolidated new offices which could cost $500M when completed.

A final possibility is that Steve Jobs could think big. "Consider this," Fortune proposed. "Just for kicks, with the money burning a hole in Apple’s pocket, he could easily buy TiVo, Netflix and Circuit City, and still have plenty left in the bank."

TMO notes, however, that Apple will probably focus on companies that know how to make big money, not lose it.