Harvard students are no longer the only ones cyber-stalking their classmates and professors on thefacebook.com. With the click of a keyboard and squeak of a mouse, students at Columbia University and Stanford University can now track down that hottie in section or get help with problem sets.

Mark E. Zuckerberg ’06, the website’s creator, opened his online networking service to Columbia last Wednesday and to Stanford the day after.

Beginning today, students at Yale will also have access to thefacebook.com.

According to Zuckerberg, the total user count rests just shy of 7,500, but users at the three schools can only access profiles of people at their own universities.

“It is the people you are likely to meet when you walk outside your dorm,” said Zuckerberg. “You might not meet that person from Columbia that you are randomly connected to.”

Although Zuckerberg would not comment on the number of users at Columbia and Stanford, students at these schools reported 37 and 26 student profiles, respectively.

In spite of the low user counts, some students at Columbia and Stanford seem hopeful that the site will gain popularity. Additionally, the site encourages Harvard students to get friends at Columbia and Stanford to join their own thefacebook.com communities.

“The concept is great. We’ll see how quickly it picks up,” said Ady Barkan, a sophomore at Columbia, who said he sent news of the site to 50 or so of his friends.

Rosabelle L. Oribello, a sophomore at Stanford, said that the site reminded her of Friendster, an online networking service. “It looks pretty cool,” she said.

Peter M. Strait, a first-year at Columbia, said he was skeptical about the site’s future success. Columbia already has a similar webpage, the Columbia University (CU) Community, which has features unavailable on thefacebook.com such as an online journal.

“The CU Community has exploded,” said Strait. “[On thefacebook.com], I felt my options were limited.”

Strait noted, however, that thefacebook.com offered some networking features worth exploring.

The frenzied popularity of thefacebook.com at Harvard had attracted 5,055 students to the site as of yesterday.

Zuckerberg continues to improve the site with help from his roommate Dustin A. Moskovitz ’06, who is writing the bulk of the programming needed to add the new schools.

“[Expansion] seemed like the natural thing to do,” said Zuckerberg.

In order to expand, Moskovitz and Zuckerberg had to write computer programs that would “parse the course catalogs and student newspapers” of the additional schools.

Following Columbia, Stanford and Yale, which Zuckerberg said took about three hours each to set up, he hopes to open the site up to Boston-area schools like Boston University and MIT.

Zuckerberg currently pays for the server space—which he said costs about $85 per month—out of pocket, but even that may change as thefacebook.com evolves.

“It might be nice in the future to get some ads going to offset the cost of the servers,” he said.

—Staff writer Adam P. Schneider can be reached at aschneid@fas.harvard.edu.