The Tripit Java Sample Code by Tripit demonstrates API communication with authorization, requests, and responses. Examples include traveler's map and client's itinerary. Additional API information is available at https://www.tripit.com/developer
Cycling in the UK is not only a popular past time but and also a real commuting choice. The UK has numerous defined cycle routes and many towns and cities have designated cycling lanes and more recently London introduced a cycling scheme fondly referred to as Boris' Bikes after the current Mayor of London. Since more and more people are using a bicycle as a preferred method of transport, and with cyclists having a different selection of routes, on top of the ordinary street network, than alternative transportation methods, it makes sense for there to be a need for a bicycle journey planning web application and API.
Travel reservation site Expedia starting working on its Expedia API back in 2009, according to the changelog. It has three APIs, covering hotels, flights and cars. Don't be shy. Expedia has been expecting you. The Expedia developer site has all the warmth and care of a fine bed and breakfast. They clearly want to invite you in, make you comfortable, and get your development project of the ground. Though they do have a couple hoops to jump through, as well.
Google has added one of the most popular features of its consumer Google Maps product to the Google Maps API. Predictive travel time is oft-used by consumers to find best routes, and avoid traffic. Now, developers have access to the feature and can integrate the functionality into third party apps.