A dedicated Google Places app just launched for the iPhone, which is another alternative for using Google-based local search functionality on a mobile device.
The new app is focused on discovery more than search. The Apple produced Maps app is more search focused--directions and navigation.
The new Places app is dedicated to finding businesses and browsing set categories--the dashboard layout is an icon, grid, browsing menu that directions to business listings using a location based input. The app also branches out into a recommendation engine based on Google Hotpot, which shows friends' ratings and reviews.