Christina Wang has her date-night routine down pat. She combs her hair, fixes her makeup and then checks her phone, hoping to find Mr. Right, who might just happen to be nearby, right now.

Wang, a 20-year-old psychology student at St. John’s University in New York, is among the growing pool of people using cellphone applications that let them make an instant date, based on who is in the area and available to grab a drink.

The idea of meeting someone on the fly through a mobile app based solely on proximity may seem, at first, like merely a pretense for facilitating a one-night stand. Operators of these services say they are aware of the potential pitfalls and allow users to control how much information they divulge. Users say it’s another step in the continuum of courtship — always fraught with peril — from traditional matchmakers to personal ads to online dating.

And Wang and others who use these services — typically people in their 20s and 30s — say they are a slightly updated version of Internet dating sites. They say the services allow them to skip the more elaborate mating rituals of standard online dating, which seems to move glacially in an era of texting and social networking.

"It can take a month to actually meet up with someone that you’re messaging online," Wang said. Mobile services allow for a "quicker jump from virtual meetings to actually meeting."

On the apps, which use smartphone location technology, users post a simple profile and then broadcast their availability, or scan a list of others who have done so. They can immediately exchange messages and, if there is mutual interest, decide where to meet.

Some of the apps are stand-alone, while others are new features of established dating sites; there are fewer than a dozen so far, including Blendr, OkCupid Locals and HowAboutWe. They tend to be free, making money by selling ads or charging for extra features.

OkCupid Locals is part of OkCupid, a larger dating site, which says a tenth of its 2.5 million members use the mobile app. HowAboutWe began a little more than a year ago as a website where people post suggestions for dates they would like to go on. (One recent idea: "How about we go on a cupcake tour of Manhattan?") It released an iPhone app with location features in June. Since then, the company says, more than 100,000 dates have been posted through the app, or roughly 30 percent of the total dates ever posted on the service.

The trailblazer among these services is Grindr, which is geared toward gay men and has signed up 2.6 million members in the 1 1/2 years it has been in business. In late summer its creators released Blendr, aimed at people who have similar interests. The creators of Grindr and Blendr don’t say their sites are strictly for dating, but Grindr promotes dating as one of its uses.

Grindr has earned a racy reputation in part because it features only a user’s profile picture, his location and a very short description. The newer services try to avoid this problem by allowing users to give more information about themselves. They also try to address safety concerns that might prevent mainstream adoption by letting users control who can see their profile, obscure their exact whereabouts and skim through prospective dates without revealing where they are.

Wang said it was easy to weed out the weirdos with a quick exchange of messages. She said the men she met through the OkCupid Locals app were of the same caliber as those she had met through online dating sites.

"Nothing traumatizing has happened on either," she said.

Tom Critchlow, 28, an online marketer who lives in New York and is a frequent user of OkCupid Locals, said the downside was that "it is so immediate, it can give off the connotation that people only want to meet up for sex," something he found unsettling. If the service is to be successful, he added, "they have to get around that, because it can come off as creepy."

He said that while he’s had success meeting friendly women through the app for a drink or dinner, it was still hard to shake the notion that there was something sordid about scanning profile pictures ranked according to who is closest.

Older dating sites like Match.com and eHarmony see opportunity in the local-dates game. Match.com bought OkCupid in February, and eHarmony released a service in August called Jazzed with a location-conscious mobile app. It says that app has been downloaded more than a quarter of a million times since then.

Still, Match.com says it has no plans to add location features to its main service, which tries to help people find long-term partners.

"People in their 20s and 30s date very differently," said Mandy Ginsberg, the site’s president. "The average age of our users is late 30s and 40s, and 50 percent have been married before or have kids. So it hasn’t come up in requests."

Michael Bolognino, 32, who lives in San Francisco and works in marketing, said he had had his fair share of people looking for action and nothing else on Grindr and OkCupid. Even so, he managed to meet his current boyfriend of two months using OkCupid Locals — and the previous one, whom he dated for a year, on Grindr. He says the lower level of commitment involved with these services is actually a bonus.

"In a way, it feels less risky, because you’re just meeting for a quick interaction and getting a vibe," he said.

Frequent browsers on these services say there are other drawbacks to using proximity as a factor in a dating search.

"When I’m home and check it, the same five guys always show up," said Shana Hensley, 29, who lives in Denver and works as a wedding photographer and at an Apple store.

But for Hensley, convenience trumps the shallower pool of bachelors.

"Time is a huge factor," she said. "I can check it at lunch or riding the light rail downtown and see if there’s anyone free to get a drink after work."

Michael I. Norton, a professor at Harvard Business School who researches how people interact online, said people had always looked for love nearby. For example, he said, "We go to the same concerts and bookstores in the hopes of meeting someone who likes our favorite band or author."

"To older people," he continued, "these services feel more intrusive, but younger people are used to the Web. At some point, this kind of interaction may become the default."

© 2011 The New York Times Company