There are now more ways to get the inside scoop about an employer -- before you are hired.

In the latest expansion of the Web phenomenon of social networking, more sites are launching features that make it easier for job seekers to connect with the employees of prospective hirers. Still, before you gather around the virtual water cooler, keep in mind that on many sites, what you post can be viewed by anybody -- including your current or future boss.

Jobster Inc. is scheduled to launch a revamped job-search Web site today that includes people's posts on what it's like to work for their employers. Job hunters can link to these employees and ask to contact them.

At the same time, social-networking Web sites are expanding into the professional arena. In May, Facebook Inc., whose Facebook.com Web site is popular with college students, started letting users log in with their work email addresses to connect with fellow employees. Users could previously log in only with their .edu email addresses, which restricted the Web site to students, alumni and faculty.

In April 2005, LinkedIn Inc. announced the integration of a broad job-search engine into its Web site, which has traditionally served as a networking tool for professionals. You can click on a link to see if any of your online contacts -- or their contacts -- work for employers who have posted job openings. Even networking giant MySpace.com, the social-networking Web site owned by News Corp., has joined in: It added a basic job-search engine powered by Simply Hired Inc., which runs LinkedIn's engine, to its site in June.

Until recently, social networking on the Web was confined to hubs for young people seeking to meet and chat. Now, there is growing interest in adapting social networking to the business world -- both among networking sites looking to expand their reach and among job sites seeking to offer new services. One result: People who are searching for work have more one-stop shops for making connections, getting referrals from employees, and finding out the inside scoop.

The new Jobster site, which so far has been tested on about 2,000 people, allows users to answer questions about their workplace. Their answers can give prospective hires more information about the employer and company culture, says Jobster Chief Executive Officer Jason Goldberg. The questions on the test version of the Web site range from what employees are reading to what the interview process is like.

The blurring of the lines between searching for jobs and making friends online raises the question of who is reading what you post. Employers could easily monitor Web sites to see what employees are saying. Most sites are free, and at Jobster, people can use much of the site without logging in. To get access to most of LinkedIn and Facebook, you have to be a member and log in with a password. But employers could still join and see what prospective hires post about themselves in their profiles.

Facebook now supports 7,000 work networks representing employers including companies, nonprofit groups and the military. Facebook allows everyone in a network to see each other's profile. Job seekers can't view the full online profiles of employees outside their network. But they can search to see if someone belongs to a certain network and send a message or a request to be added to his or her list of friends.

For job seekers, reading online posts can lead to misimpressions. People tend to complain more than compliment. And what they post may not necessarily be true. On one online job board, a user complains that "there is no work-life balance" at a particular accounting firm. Another user criticizes the interview process for a marketing job, protesting that the company is "very, very inconsiderate to your time." Elsewhere, one worker writes, as part of a job description: "Collect owed tax money from the poor american souls in the Self-Employed/Small Business Area."

Some employers are wary of such sites. "A company should want to have some control over what is being said about them," says Ben Gotkin, lead corporate recruiter at Mitre Corp., a McLean, Va., company that manages three federally funded research-and-development centers. "You don't just want people to go out and blast you." He says Mitre will wait to see how the employee posts are regulated on Jobster before encouraging its employees to participate in answering the questions.

Some job sites have added social-networking components without including employee posts. LinkedIn.com plans to add employee surveys on issues like salary and workplace culture in August, but it has stopped short of adding message boards, since it would be easy for employers to figure out who said what, says Keith Rabois, vice president of business and corporate development at LinkedIn. The company is looking for ways to get around that hurdle.

"It is very difficult to make the experience something other than disgruntled ex-employees venting about their former employer," says Marc Cenedella, president and CEO of TheLadders.com, a Web site that posts jobs that pay more than $100,000. TheLadders.com has considered adding a space for employee comments but so far has rejected the idea. "We have not yet found the secret to eliminating that noise and distraction to make something of real value for the job seeker," he says.

Still, negative comments from current and former employees can make job-seekers aware of the cons in working for a company. "I think disgruntled employees have something to say that's worth hearing," says Jim Ivers, a 26-year-old M.B.A. student at Boston University. But he adds that when reading a complaint, job seekers should consider it just one opinion.

He has found that contacting employees can be helpful in a job search. Mr. Ivers, who is an intern at T-Mobile in Bellevue, Wash., this summer, went on Jobster.com last spring to find out more information about the company. He found four online referrals from company employees.

People posting information online should know that anyone could be looking at it. Users are typically less savvy on social-networking sites like Facebook than on career-oriented Web sites, says Steven Rothberg, president and founder of Minneapolis-based CollegeRecruiter.com, a career Web site for college students and recent graduates. For instance, he says, if users are planning on joining a workplace network on Facebook, they might want refrain from posting personal photos.

It can be damaging "if you let your hair down a little too much and you start to write about how you hate your boss, how you cut out a little early on Friday and no one really knows it, how the companies' products are defective," he says. "There are great risks. There are also lots of great opportunities."