Flash memory is a hot commodity right now. Companies like Intel (NASDAQ:INTC) and Micron (NYSE:MU) are reaping the benefits of a boom in mobile technologies like super-thin laptop PCs, smartphones, and tablets because of those devices’ reliance on solid-state drives.

A hyped new IPO like Fusion-io (NYSE:FIO) excites investors because Dell‘s (NASDAQ:DELL) servers, part of that company’s booming service segment, uses Fusion’s flash memory. As do Hewlett-Packard‘s (NASDAQ:HPQ) servers.

Here’s the big secret about the flash memory business, though: Like so much else in the tech sector, it lives and breathes according to Apple (NASDAQ:AAPL).

According to an IHS iSuppli report, Apple has beaten out H-P, Dell, IBM (NYSE:IBM), Nokia (NYSE:NOK), Sony (NYSE:SNE) and all others to become the single largest consumer of semiconductors on the planet, spending $17.5 billion total in 2010. Those purchases are to grow Apple’s famous portable devices, particularly the iPhone and iPad. These devices use solid state drives for their storage, and the core of solid state drives (as well as USB flash drives and memory cards) is NAND flash memory. At the moment, Apple accounts for more than half of the entire business.

Flash memory, of course, isn’t the only component in popular gadgets where Apple is the primary customer. A February report from DigiTimes said that manufacturers now claim that Apple controls 60% of the capacitive LCD touch-screen supply. The iPhone and iPad use the same touch screens as those found in Motorola‘s (NYSE:MMI) Droid phones and Hewlett-Packard’s touch-screen PC monitors. 

Although it’s just a fraction of the amount spent on semiconductors, Apple did devote nearly $4 billion in January just to secure contracts with its component suppliers. LCD screen manufacturers like TPK, Sharp, and Wintek know they’re beholden to Apple even as competitors like Motorola buy up whatever is left.

The control Apple is exerting over the computing industry should definitely be a concern to certain companies. After all, technology changes quickly. Hard disk-drive makers like Seagate (NYSE:STX) and Western Digital (NYSE:WDC) already have cause for concern with traditional PC sales down more than 1% in the first quarter of 2011, but the changing nature of Apple’s business will begin to affect them before too long.

Apple’s iPod media players already switched away from using hard disk drives in favor of flash memory when the company introduced the iPod Touch in 2007. Evidence suggests that Apple is beginning to phase out the entire iPod product line though, meaning that whatever remaining market for the hard drive-based iPod Classic still exists will disappear. Deutsche Bank analyst Chris Whitmore also believes that Apple’s next MacBook Air laptop, which also uses flash memory rather than a hard drive, will account for half of Apple’s total laptop business this year. How many more years until an entire segment of the technology manufacturing industry loses Apple as a client?

For shareholders, Apple seems to be a golden goose. You can’t blame other investors for being concerned about that goose’s influence on the fortunes of the broader technology market, particularly those companies who are, or will no longer be, suppliers to Apple.

As of this writing, Anthony John Agnello did not own a position in any of the stocks named here. Follow him on Twitter at @ajohnagnello and become a fan of InvestorPlace on Facebook.