Looking at the docs for this method, it would appear that you need to be a little more specific than just "Atlanta". However it would appear that the method is in fact broken. In the project I'm working on something I've come across a few broken methods. This may be one of them - I've just tried it with a GPS fix instead of a verbose location and it's still not working (nor is it working with a radius thrown in either).
Sorry for the delayed response. Whilst the majority of the methods are fine, the couple of broken ones around mean I've had to cut a couple of features from the iPhone app I'm building. But I'm nagging the Upcoming folks every so often to ask them to fix them :)-N
We recently had an issue with venue.search where a 'search_text' parameter was required -- e.g., if you just call venue.search with a location and no venue name, you would not get any results. We have actually fixed this issue in our most recent release, so I recommend trying your call again at http://upcoming.yahoo.com/services/api/exp...od=venue.search and update this thread if you see any further issues.