What makes a trip to a restaurant a great experience is not just the fact that they serve delicious food and good wine, but it has a lot to do with the atmosphere and overall 'vibe' of the place. Of course, a 'good vibe' means different things to different people (some like it chilled and some like it loud and bustling), so imagine how cool it would be to be able to browse through dining options based on the exact atmosphere you're looking for. That's what Hoppit is all about; finding restaurants by atmosphere. Hoppit's API provides access to this handy functionality.
With Twitter reducing its search history to four days, it is a challenge for applications that are dependent on search results, that went not days but even months back. Several applications have taken on the challenge to fill this void and are building search indexes on top of Twitter. Topsy is one of them and it's sharing its results as an API.