Mobile social network Loopt has upgraded its location-aware service with a new feature called Pulse. Pulse lets users search through their friends’ recommendations and comments, as well as local content fed in from over 20 new sources like Zagat, CitySearch and DailyCandy.

The upgrade also includes new LocationPoint ads from Nokia’s mobile mapping division NAVTEQ; the ads can be coupons tied to restaurants and stores in the users’ vicinity, and include click-to-call and click-to-route functionality. Loopt’s service previously included ads, but new sponsors like Target and Chili’s have signed on to run Pulse-specific campaigns (per the NYT).

In a statement, Loopt co-founder and CEO Sam Altman said “local discovery has never been done very well”—a hint that the company is trying to evolve its popular service into more of a mobile search and content platform, than just a fun way to keep track of friends and their locations. Loopt recently acquired GraffitiGEO, a fellow location-based app developer that had been