The forthcoming Yelp update for the iPhone adds a number of new features as well as brings more of Yelp over from the PC side. The new features include:

• Sales and deals near you: this is content that exists on Yelp that will now be available via the mobile app (the change may motivate more businesses to add sales and deals)
• Maps: offer improved search and now they now take advantage of multitouch and can be pinched, zoomed and expanded
• Talk: this is a feature on Yelp on the PC. However, now you can read and respond (Q&A) to community posts in mobile (becomes Twitter-like on the iPhone)
• Comment on reviews: users can choose buttons that label reviews useful, etc (ranking/rating reviews). In addition, you can send the reviewer a compliment. Those on the receiving end can also reply. 

Click the image below for a video tour of the new features:

What's striking is that when Yelp first launched on mobile, at the behest of Palm three years ago it was kind of a fun experiment. Now mobile has become a strategic part of the business.