Yelp 4.0 update lets others know your business

Yelp, the fast-growing local search and review site, has announced an update for its iPhone app. Version 4.0 of Yelp for the iPhone and iPod touch allows you to log in to your profile and edit it. More interesting, the app also includes a "check-in" feature which tells your Yelp friends that you're visiting a particular business.