Taking a dizzying spin through the video chat service Chatroulette can be highly entertaining — you might stumble onto a celebrity or an impromptu performance by a pianist.

But there’s always the chance of encountering something unsavory on the service, which randomly matches strangers for video interaction.

One entrepreneur is hoping to limit the chances of that — at least for the collegiate set — with a new Web site called RandomDorm.

RandomDorm takes the thrilling serendipity of being paired with an anonymous stranger in a video chat room and limits it to college campuses. Participants need a college e-mail address to access the Web service. Alternatively, they can sign in using Facebook as long as the primary e-mail address tied to that account ends with an .edu.

Tying the users to a specific identity will in theory make them more accountable, although it’s unclear whether RandomDorm’s limited pool will increase the chances of seeing someone chugging beers online or performing more extreme college antics.

“The good thing about Chatroulette is that it has a low barrier to entry. Anyone can hop on and be instantly connected to someone in the world,” said Josh Weinstein, creator of RandomDorm. “We hope to emulate that simplicity and ensure a degree of community and security.”

For now RandomDorm is limited to students at schools in the United States, but in the future, the company hopes to open it up to international universities, as long as there is demand.

According to recent findings released by the research firm comScore, the demand might be stronger than he thinks: Male college students were the most avid users of Chatroulette.

This isn’t the first time Mr. Weinstein has created a service with students in mind. He’s also the creator of GoodCrush, a college matchmaking service housed at the Manhattan branch of the Polaris Ventures-backed incubator Dogpatch Labs.

Originally, he said, the plan was to add an instant-messaging feature to GoodCrush, but when the company saw how popular Chatroulette was among college students, his team decided to switch gears.

“We put the brakes on text-based chat,” he said. “We realized there’s a real exciting opportunity to actualize our vision of connecting student bodies.”

The pop-culture record shows that most artificially intelligent assistants don’t work out too well for their human masters.

There’s the comically co-dependent — and largely unhelpful — duo from Star Wars, C-3PO and R2-D2. And who could forget HAL 9000, the glowing red orb from “2001: A Space Odyssey,” with a slightly murderous malfunction?

A start-up called Siri, based in San Jose, Calif., hopes to do a slightly better job by bringing a virtual personal assistant to your pocket — more specifically, to your Apple iPhone.

Various riffs on the virtual personal assistant concept have been around for while. Remember the Milk and Jott are examples of electronic crutches intended to help users be more efficient and complete tasks. And during the dot-com era, there was a great deal of hype about a coming generation of digital “agents” that were supposed to go out and perform various tasks for people on the Web.

But where Siri breaks away from the pack, says Dag Kittlaus, co-founder and chief executive of the company, is that it is “speech recognition with a brain.”

“This is the first version of a computer assistance that understands language, has the ability to delegate tasks and learn,” Mr. Kittlaus said.

First, users speak a command, like, “Find a table for two at 9 tonight,” “Get two tickets to ‘Crazy Heart’ at 8,” “Send a taxi to my house,” or even “What kid-friendly events are going on in New York this weekend?” Using G.P.S. and speech-recognition technology powered by Nuance, the application translates the spoken command and uses a set of algorithms to search for the answer.

Mr. Kittlaus describes the application as the “mother of mash-ups” because the company has partnered with several companies, including OpenTable, MovieTickets, StubHub, CitySearch and TaxiMagic, to generate results.

Siri is a “do engine rather than a search engine,” Mr. Kittlaus said.

Siri, which was founded in 2007, was incubated in SRI International, as part of a DARPA-financed artificial intelligence project called CALO, or Cognitive Agent that Learns and Organizes. As a result, Mr. Kittlaus said, Siri will learn more about its user and tailor its results based on preferences over time.

“This is intended for everyone to help in their menial tasks,” Mr. Kittlaus said, “not just for someone in a corner office.”

To make money, the company says it receives a small fee from any monetary transactions, like purchasing movie tickets, that are conducted through Siri.

Recently, the company closed a $15.5 million Series B round of venture financing, led by Li Ka-Shing, a Chinese billionaire who has also invested inFacebook and the music streaming service Spotify. Previously, the company raised $8.5 million from Menlo Ventures and Morgenthaler Ventures.

Currently, Siri is available only for the iPhone, but the company intends to also offer versions compatible with Android phones and BlackBerrys.

The company also hopes to introduce features that will allow users to send requests to Siri via e-mail and instant message.