In ongoing work that is part of the Human Microbiome Project, researchers in Jeffrey Gordon's lab at the Washington University School of Medicine in St. Louis showed that lean and obese mice have different proportions of microbes in their digestive systems. Bacteria in the plumper rodents, it seemed, were better able to extract energy from food, because when these bacteria were transferred into lean mice, the mice gained weight.
I was recently looking for an API with this kind of data and found that votesmart.org has a pretty good one that offers information on federal, state, and local government representives, legislation, votes, and more. http://votesmart.org/services_api.php
Also, the Sunlight Foundation has an API with congressional data, and they are currently holding a contest for creation of any kind of application that would help improve accountability, transparency, and interaction in government. The app has to be released under the MIT, New BSD, or GPL family of licenses. First place prize is $15,000. Submissions are due by March 31st. You can read more here: http://www.sunlightlabs.com/appsforamerica/
I am not associated with VoteSmart or the Sunlight Foundation.