I just heard from the good folks at Yelp that they’ll integrate OpenTable reservations on Phone, iPad and Android apps. The free app update is already live in iTunes and Android Market.

This extends each company’s logical tie-ins (already present on the desktop) to mobile. It can be argued that the integration makes more sense in mobile, where portability and location awareness translate to higher levels of immediacy and commercial intent.

“When we looked at the data to see how consumers are using our mobile apps it became clear that they are super engaged,” they told me in an email. “So adding in more functionality to our app was an easy decision.”

We’ve heard the same from OpentTable consumer marketing director Scott Jampol. Its numbers have surely grown but last we checked, it sat 3 million diners ($150m GMV) via mobile.  Mobile users also convert at higher levels and with greater immediacy (table now vs. this weekend).

Yelp likewise has its fair share of interesting mobile data that point to higher levels of user engagement. We reference these figures often, and they were recently cited by CEO Jeremy Stoppelman at our ILM:10 show.  Today, a fresh batch of data join the announcement.

— 3.2 million unique visitors used a Yelp mobile app
— One in three searches on Yelp.com came from a Yelp mobile app
— Every other second a consumer generated directions to a local business
— Every other second a consumer called a business from the Yelp business
profile page
— A photo was uploaded every 30 seconds from a Yelp mobile app

One of the amazing things about the 3.2 million figure is that Yelp’s total monthly uniques are about 45 million. That’s about 7 percent mobile usage, however mobile represents almost a third of overall Yelp searches. To the points made above, it shows how mobile users are more engaged.

They’re also more likely to call, click, or visit a business, representing good monetization events if and when Yelp eventually flips that switch. The company has understandably been quiet about this, but I believe we’ll see it happen this year.