There's Google My Business, a local directory that also has Google reviews baked in. There's Apple Maps Connect, which is its own local directory with ratings and reviews. And you know you need to keep your eye on Yelp, the mother of all review sites.
Now Facebook wants to join the party too! Introducing Facebook Places, another local directory that you might use some time when your Yelp app won't load. The Web-based service (it hasn't yet been baked into the mobile app) simply prompts you to "Discover great places in every city." Enter a location and wham, bam, boom: You get cool stuff to do, all with reviews by real Facebookers.
Again, it screams "Yelp competitor," and really, it is. And you need to keep your eye on it.