A little after 8 am last Thursday, Tom Fitzgerald stood in the rain at Northeast 22nd Avenue and Oregon Street. I stood inside Urban Grind, the spacious cafe at this sleepy corner just off Sandy Boulevard. He could see me. I could see him. We were talking to each other on the phone.

The only thing that made this behavior anything other than stupid was how we were talking. The call was made without owing a cent to a local phone service. Using technology many of Portland's hyper-committed geek activists believe is the Next Big Thing, Fitzgerald and I bid sayonara to Qwest's standard phone system and spoke through cyberspace. Over the Internet, he came in loud and clear.

Fitzgerald and Aaron Johnson--volunteers for Portland's nonprofit Personal Telco Project--drilled me in the basics of Session Initiation Protocol. Tech-speak aside, SIP converts human voices into digital signals that move over the 'Net. Users can call anywhere without using standard phone lines--or paying a dime for long distance.

"It's a complete flip," Johnson says. "People used to use their phones to get their computers to the Internet. Now you can use the Internet as a phone line."

The phone at Urban Grind, which Johnson hooked up last week, is the only free public Internet phone anywhere, as far as PTP knows. Anyone can walk into the cafe and give the phone a whirl for the price of a latte, opening a new front in Personal Telco's campaign to install free wireless Internet across Portland.

Which is not to say you'll be able to call Grandma in Sheboygan just yet. Right now, it's only practical for Internet-phone users to call other Internet-phone users. In part, that's because SIP phone numbers work on a six-digit system, not a 10-digit system. (It is possible to have your SIP number translated into a 10-digit number, which is how Fitzgerald was able to get my call on his cell phone.)

This lack of integration with mainstream phones makes Internet phones something of a private club. Even for the SIP-savvy, calls don't always go through. The complex weave of noise created by two human chatterboxes is harder to transmit than emails, images or sound files, which are stored whole and forwarded across the Net with no real-time requirement.

"Sound is real-time, or it's annoying," Johnson notes.

Urban Grind, as any of its thick crowd of morning laptop jockeys could tell you, offers free wireless Internet access. But SIP phones can work on hardwired broadband connections, too, and an Internet phone number follows its master anywhere. You can use something that looks like a regular phone but has an Ethernet jack in the back, or a "softphone," an application that mimics a phone on your computer screen.

The infrastructure to guarantee quality connections for every call isn't there yet. But for people and organizations that can save by declaring independence from the global phone grid, the technology is already paying off.

"Let's say Aaron and I work for the same company, but Aaron's in Tokyo for a conference," Fitzgerald says. "I can dial through the Internet no matter where he is, and we don't pay long distance. I'm going to set up my sister in Arizona and my sister in New Hampshire, and then they can talk their heads off for hours, for free."

This prospect does not please Qwest, nor any other commercial phone company. The battles over Internet phone regulation remain to be fought. But PTP activists see a near future when Internet phones are as ubiquitous as cell phones have become.

"My son in the U.K. has broadband, and I'm going to send him an SIP phone," says Nigel Ballard, a transplanted Brit who serves on Personal Telco's board. "My SIP phone rings here in Portland, and we can chat for as long as we want without incurring any costs. Now how can that not be the next big thing?"