I like their mapping capabilities and their yellow pages. I use yahoo local instead of a physical phone book most of the time.

Yahoo! seems to be pushing really hard in the local search space. They're already the most advanced in terms of features - they're mapping tool is awesome and allows you to pinpoint multiple merchants in a neighborhood. The are pushing user reviews aggressively, which I think could be a difference maker. And today, they announced a feature that lets users send local search results from their computer to their cell phones. They seem to be doing all the right things and are certainly throwing a lot of money at innovation.