The Take.io API from Brazil has a REST protocol with data formats in XML and JSON. According to Take.net, "The take.io RESTful API currently defines five services: SSO, Core, Billing, Messages and Reports." The company states further that, "Take.io is Take.net DNA translated into a set of APIs designed to allow companies to use SMS, MMS, voice, pricing, location, CRM, etc., all of which are integrated with their existing systems."
There have been a lot of new socially based mashups showing up recently. In fact, we recently topped 700 social mashups. While many of these use the Facebook API or Twitter API, there are many more social APIs. The mashups below run the gamut, though, yes, also include Facebook.
Stereomood is a streaming music service that gives recommendations. To start, it uses a list of moods, each of which have an associated playlist. While playing songs, users can like or ban songs, much like Last.fm or Pandora. The Stereomood API allows full access to the site's functionality to developers, allowing developers to make fully usable clients on any platform.