Google Places comes with a preset list of searches of business categories - the list is easily edited to reflect your preferences - and quickly displays nearby results for your queries. You can save favoured results with a star, read reviews of that business from 'across the web', and even contribute your own ratings and reviews. As a result, Google Places offers a wider range of opinion than the similar Yelp app, while allowing more input than the venerable Places app.
One minor complaint: Google Apps is inconsistent in how it uses maps. Search a category, and you have the option of viewing an in-app map showing all the nearby businesses of that type. If you want a closer look at the location of a particular business, though, you're whisked without warning to the iPhone's native Maps application. It's annoying to have to flip back-and-forth between apps.
But, because it draws upon the huge databases of Google itself, Google Places is still a great, useful tool for any iPhone user who ever leaves their own neighbourhood.