To save money in these tough times, universities, conference planners, and global companies have started holding gatherings for far-flung employees and students in the online world known as Second Life.

Sun Microsystems Inc., a Silicon Valley tech company, has only one rule: Employees should show up looking like humans.

Other companies don’t seem to mind if their workers take the form of animals and other entities while they’re on the clock.

On a recent afternoon in Second Life, about 20 avatars — the personalized character each inhabitant of the virtual world adopts — gathered for a lecture on software development sponsored by Intel Corp. The semiconductor giant planned the event to spark conversation about complex technical topics among employees and others across the globe.

The Intel employee who opened the event was a tuxedoed half-man, half-lynx. He turned over the talk to an avatar in a tight, white shirt who called himself Zombie Bob. In the audience, a woman with a ponytail and sunglasses slept in the front row, a blue-skinned man with spiky hair listened attentively and another, clad in jeans and a T-shirt, stood in the background with her arms extended as if being crucified.

Meanwhile, a man wearing a rocket pack jetted in and out of the room.

Corporate America is learning to embrace Second Life, where creative self-expression is expected. Since Linden Lab, a San Francisco company, opened the online community to the public in 2003, it’s been an eclectic place where strangely appointed avatars meet, build fancy palaces, go sailing, buy virtual goods, and have cybersex.

Where people are, marketers want to be. Two years ago, companies such as American Apparel and the footwear maker Adidas started filling Second Life with stores and buildings. The virtual world’s early inhabitants, who largely disdain anything with a corporate tinge, rebelled by launching terrorist attacks and starting gunfights in the shops. Faced with empty storefronts and ridicule, many companies pulled out.

Now, other companies are carving out parts of Second Life as their own. They are creating employee-only islands and office buildings, then encouraging their staff to meet there. Compared with plane tickets and hotel bills, it’s not that expensive: A 16-acre private island in Second Life costs $1,000 plus a $295 monthly maintenance fee.

And instead of staring at white walls during conference calls with strangers, employees can wander a virtual paradise and see representations of the co-workers they have never met.

Forrester Research, a respected company that focuses on the technology industry, recently highlighted the potential for its clients in a report titled “Getting Real Work Done in Virtual Worlds.”

Swiss construction giant Implenia, for instance, worked with IBM Corp. to test ways to turn off lights in real buildings by flipping virtual switches in Second Life. The University of Maryland simulated a highway emergency and had participants respond in a different virtual world, designed by Forterra Systems Inc. And a company called Qwaq created a zone of oil rigs, refineries, and offices to enable energy professionals to walk through their properties and discuss repairs while viewing actual equipment.

“Virtual worlds are relatively inexpensive, don’t require a great deal of start-up technology infrastructure, and provide a naturalistic, immersive approach to simulating space, people, and objects,” two Forrester analysts, Erica Driver and Paul Jackson, wrote.

IBM, which has nearly 387,000 employees in 170 countries, began building in Second Life in late 2006. Now, about 5,000 workers visit Second Life and other virtual worlds to conduct meetings, train employees and hold orientation sessions. In April, the Armonk, N.Y.-based company said it would become the first to host private regions of Second Life on its own computer servers, which provide more security and privacy than the islands hosted on Linden Lab machines.

Second Life helps IBM learn how to make meetings more efficient, the director of services research at IBM’s Almaden Research Center, which frequently uses Second Life and other virtual worlds, Jim Spohrer, said.

If someone goes off on a tangent during a meeting, he said, colleagues send messages telling the person to get back on track. If an avatar falls asleep on screen, that’s a good sign the staffer isn’t paying attention. In fact, it means he or she has stepped away from the keyboard. Salespeople try out pitches in Second Life, and they’re recorded, played back, and critiqued by colleagues.

The eccentricities of the virtual world also lead to social connections that aren’t possible on conference calls. For instance, Mr. Spohrer said, avatars sometimes bring their virtual pets to meetings and chat about them or invite colleagues back to their Second Life homes to show what they have built.

Early on, Mr. Spohrer said, employees designed bizarre avatars even for client meetings. But most are getting more serious now.

Like other companies in Second Life, IBM has laid down ground rules. It instructs employees that if they “encounter behavior that would not be acceptable inside IBM, you should ‘walk away’ or even sign out of the virtual world.”

At Santa Clara, Calif.-based Intel, human-resources executives and lawyers decided that if employees use “Intel” in their avatar names, they are forbidden to visit Second Life’s many strip clubs or other virtual houses of ill repute.

“If you’re there with an Intel last name, you have to behave as if you are representing Intel,” an engineer with the Intel Software Network, Paul Steinberg, said.