One hallmark of the Internet era has been the speed at which young engineers and college kids manage to single-handedly threaten or even replace obsolete business models. Jerry Yang of Yahoo! and Larry Page of Google are such nerd-rebels, as are more recent pioneers such as Shawn Fanning (Napster), Chad Hurley (YouTube) and Tom Anderson (MySpace).

Armed with technical and business acumen, and empowered by the wide availability of broadband Web access, these new entrepreneurs have been busy tearing down old distribution channels for text, music and videos, all of which we now lump together and call “content.”

In that way, they’re descendants of the “Homebrew Computer Club,” a group, including Apple founder Steve Wozniak, that first met in 1975 in the Menlo Park, Calif., garage of engineer Gordon French, who built a homemade computer using an early Intel chip. The club members, let’s be frank, were hackers, restless geniuses eager to defeat obstacles imposed by IBM, Hewlett-Packard and their other employers.

While the Homebrew Computer Club messed with hardware, the MySpace generation has focused on software and content.

Now a new type of renegade-innovator is on the rise: Folks who try to upend the business models of wired and wireless networks. Voice-over-the Internet pioneer Jeff Pulver is one example. But their numbers are small, mainly because networks are so difficult to penetrate and create innovative new services for. And anyway, once something novel gets invented the network operators usually move fast to shut it down.

Which is why it’s so invigorating to hear about people such as Martin Varsavsky and Matt Hamrick. Varsavsky has a plan to create a global broadband “Wi-Fi” network made entirely of users who share each other’s signals. Hamrick wants nothing less than to let people, rather than carriers, develop new features and uses for wireless phones.

Just as government policy is doomed to lag behind technology, hackers like these two are practically essential to pushing it forward.

Varsavsky is an Argentinian-Spaniard who has launched a number of companies in the 20 years since he got out of college. He formed the Spanish company Fon in 2005 with the goal of “building the world’s largest global Wi-Fi network bottom up, spreading the power of Wi-Fi around the world, with one million hot spots by 2010.”

Here’s how his plan works: Anyone with a broadband connection can create a wireless “hot spot” for himself and, using Fon software, allow other people seeking a Wi-Fi signal to use it with his permission for $3. Other Fon users (dubbed Foneros or Foneras) can log in free of charge, while the owner of the hot spot can tap into the signal of any other Fon member worldwide when traveling. Don’t have a wireless router? No problem: Fon announced last week that it would sell the $60 devices for just $5.

As of last week, more than 64,000 Foneros have signed on, making it the largest wi-fi user community in the world. Google, eBay and Web-phone provider Skype each have invested in Fon.

Carriers of broadband Internet access are not amused. They view Fon as their own version of the early Napster, illegally siphoning away revenue. Comcast and AT&T prohibit customers from selling or sharing their broadband signal (in Comcast’s words) “outside the premises.” Varsavsky says savvy Internet service providers won’t see him as a threat. Indeed, he maintains, allowing customers to roam with their wireless signal would help carriers to build brand loyalty.

Hamrick, a computer engineer, also wants to form a citizen army, but his would be an army of programmers who would address questions such as: Why can’t you look in your cell phone address book while you’re still connected to a call — or better yet, send the address to the other party? Or why can’t you store voice mail in your phone for when you’re out of a coverage area? And why can’t your cell phone dial a person’s second number if the first one doesn’t answer?

Hamrick aims to do with cell phones what French & Co. did with computers: Build them at home. His group, reverentially dubbed The Silicon Valley Homebrew Mobile Phone Club, meets to hash out details of creating a phone whose features can be customized by anyone with the right programming skills.

To Hamrick and other phone hackers, a cell phone is merely a very small PC with an operating system running a specialized software application. They say carriers should allow people to choose among a variety of third-party applications for their mobile phones.

To the carriers, of course, his plan is heretical. “If something is wrong with the phone, it could bring the network down,” wireless industry consultant Andrew Seybold told a Knight Ridder reporter.

That’s just what Ma Bell said in 1966 when a Dallas company called Carter Electronics sued for the right to attach its own telephones to the public network. The court, wisely, sided with Carter, unleashing a torrent of innovation that led to the breakup of the old AT&T, the creation of new services such as voice mail and caller ID, and, ultimately, the arrival of such “non-network devices” as computers connected to the Internet.

Mike Mills is CQ’s executive editor for electronic publishing.