The future of the Internet may come down to a battle between Google and Apple. It's tempting to see the contest as open versus closed, but that fight -- Google v. Microsoft -- has more or less been decided. Open won. It's hard to see how Microsoft's decision to copy Google's business model can be spun any other way.

Certainly Google v. Microsoft also is a case of free v. expensive, but Google's ad-supported approach can't easily be separated from its embrace of open source development and open information access.

In the case of Google and Apple, the contrast isn't as sharp. Apple's Mac OS X is based on open source Unix. Its Safari Web browser is powered by the open source WebKit browser engine. Apple remains open enough to avoid the kind of government scrutiny that ultimately hobbled Microsoft.

In the late '90s, Microsoft focused more on cutting off Netscape's air supply than it did on innovating. Apple, meanwhile, focused on products that take people's breath away. The genius of Steve Jobs is that he saw how interface and product design could serve as barriers to entry (and exit). By making great, user-friendly products, Apple has achieved lock-in through customer loyalty.

Apple customers aren't really all that bothered by the iTunes Store toll booth. It works, and that's more than can be said of a lot of online music stores. Apple's iPhone customers will probably react the same way to the iPhone App Store.

Jobs isn't so shortsighted or greedy as to go for complete control. iTunes isn't essential to buy music. There's a way around iTunes' anti-copying scheme. And if you really want, you can use a hacked iPhone. But it's not easy. And the mass market tends to follow the path of least resistance.

Google made search on the Internet easy and effective, and users flocked to it. It wants to do the same thing on mobile phones.

Apple may have something to say about this. Google is a guest on the iPhone and it may not always be welcome.

A recent Market Watch report describes how Google CEO Eric Schmidt, while serving as a member of Apple's board of directors, has had to excuse himself from Apple board meetings on several occasions due to Google's involvement in the Android open source mobile phone stack. Android phones, when they appear later this year, will compete with Apple's iPhone.

At present, there are few signs of friction. Google and Apple get along well, a friendship strengthened by mutual distrust of Microsoft. But several years down the road, Apple is likely to find itself in Microsoft's position: trying to sustain its walled-off, profitable, and very pleasant iPhone eco-system in the face of unruly innovation driven by Android developers.

Google's path to victory lies in transforming the telecom industry by bringing prices down and loosening the death-grip of mobile telcos. It wins by turning the phone into an open mobile computer.

The problem Google faces is that its mobile industry partners are more comfortable with Apple's vision of a moderated computing environment. The popularity of the iPhone proves that walled gardens, if well-tended, can be nice places to live with plenty of revenue opportunities.