The latest wave of online dating sites forgoes mysterious equations in favor of straightforward, sometimes unexpected, matching techniques.

Whereas Match.com, eHarmony and OkCupid promise to calculate your ideal mate based on your actions and stated preferences, these new sites use some interesting new criteria such as common friends, activities, alma mater or even face structure to make matches.

A team commissioned by the Association of Psychological Science recently deemed the purely algorithmic approach to online dating no more effective at predicting compatibility than a good old-fashioned chat.

We're not sure that any of the seven approaches below would be any more effective. But many of them are certainly more fun.

1. Clique: Stop Dating Strangers

When the dating world plugged into the Internet, it largely catered to the classified-style dating that preceded it — facilitating meetings between strangers who might like each other. But the age-old method of meeting dates through friends was largely ignored by online dating sites.

Clique, which will celebrate its one-year anniversary Valentine’s Day, is trying to make that method its niche. On the invite-only site, only you, your friends and people connected to you by fewer than three degrees are visible. When you’re browsing profiles, you can see how you’re connected to each person, and your friends can make match suggestions for you.

Upside: A personal reference for every potential date.

Downside: Your common friends will inevitably hear feedback about your dates.

2. Sparkology: Ivy League Men Only

Sparkology has set out to filter its community with rigid criteria. To join the site, you need to be a college graduate. If you're a man, you need to be a verified graduate of a school on the site's list of "top universities."

Payment also works a bit differently than traditional dating sites. Women pay a flat fee per month to be on the site. Men pay a small fee to start conversations, which theoretically prevents them from spamming everyone on the site.

Upside: Men have to invest each time they communicate and are less likely to do so when they aren't sincerely interested.

Downside: Although the site's founders point out that its list of top universities includes 85 schools, Sparkology is still no doubt missing some interesting, successful people who don't happen to have a top-notch college degree.

3. Nerve Dating: Less-Painful Introductions

Once a site for listing personals, Nerve Dating relaunched in 2011 with a focus on natural ice breakers. Users post mini-updates on their profiles that answer simple questions such as "What did you do last night?" Whether they read a book, saw a concert or watched TV, the hope is that it will give others a reason to connect. Browsing the site is free, but unlimited messaging costs $20 per month.

Upside: there's something to talk about when you message someone for the first time.

Downside: Another status to update.

4. SinglesAroundMe: Location-Based Dating

SinglesAroundMe is an Android, BlackBerry and iPhone app that lives up to its name. Quite simply, it uses the GPS feature on your phone to find singles near you, literally plotting them on a map. Profile information is pretty limited, but there's an option to message people to find out more if you fork over $2.95 per month or $19.95 per year. So far I have gotten one message on the network: "you are a fake!drop dead."

Upside: Dating people near you seems practical.

Downside: When proximity is the major criteria of interest, there may be reason to question the motives of people who contact you.

5. HowAboutWe: Activity Dating

HowAboutWe puts focus on the date rather than the individual. Users propose fun activities. Other users can send them messages if they like their ideas. To send such a message, however, you'll need to fork over between $7.99 and $34.99 per month depending on how long you commit.

Upside: Fewer coffee shops, more adventures.

Downside: "How about we… communicate only through facial expressions for the first 30 minutes of our date." How about not.

6. Soul2Match: Similar Faces

Soul2Match promises to match singles based solely on one piece of information from each of them: their headshot. Founders Jorn Eiting and Linda van Liempt are serious. They cite several studies that show what we’re all really looking for in our ideal mate is ourselves.

“The more two people have similarities in their faces, the more they look alike, the happier they are in the relationship, the stronger the relationship,” Eiting told Mashable in September.

The website compares your mugshot with other faces to rate your compatibility.

Upside: Entertainment.

Downside: Remember that research the company cites? Some of it shows that couples with similar levels of attractiveness are the happiest. Other research says people trust those who have similar facial features more than those who don’t.

The best proof for Soul2Match‘s matchmaking method is a 1999 study that used computer-graphic image manipulation to generate male faces that looked like female participants. For example, if a woman’s cheekbone stuck out 0.3 percent more than the average woman’s cheekbones do, the program would generate a male face with cheekbones that stuck out 0.3 percent more than the male average. Women were more likely to rate faces as attractive that had been manipulated to match their own.

Trouble is, a later study by Lisa M. DeBruine of McMaster University showed that people are more likely to rate faces similar to their attractive when it’s the same sex than photos of the opposite sex.

“The same-sex bias … is a product of specialized responses to facial resemblance as a cue of kinship,” DeBruine wrote; it helps us “favor kin in a non-sexual prosocial context and avoid kin in a mating context.”

In other words, her theory is that it’s all part of the brain’s recognition mechanism that helps us be nice to family members — and avoid incest.

7. Grouper: Group Dating

Grouper arranges group dates between three women and three men.

Upside: Less pressure and a "meet three new people for one time commitment" structure.

Downside: Here's to hoping you and your friends don't all fall for the same person in the other group.

BONUS: 12 Pinterest Boards for Valentine’s Day Inspiration

12 Valentine's Day Pinterest Boards

Image courtesy of iStockphoto, adventtr