Draw on a map and get results within that area.
Yahoo has a new iPhone app that rocks. It's a map and you can draw on an area of the map and get local biz results for just the area you've circled (or whatever crazy shape you make up).
The idea behind the app is to reduce typing. But the search filters feel limited. Generally, apps like this update over time, so hopefully even more robust search will be included in the future.
It's free and available in the iTunes App Store.