LINQ to Twitter covers the entire Twitter API, including OAuth authentication support.
New items added to the v1.11 release include support for Saved Searches, Delphi Prism, and Laconica
To use LINQ to Twitter in your own projects, perform a build of the LinqToTwitter project in the downloaded source code, copy the DLL to a common folder for your development project, and reference the LinqToTwitter.dll from your project. You should add a using declaration for the LinqToTwitter namespace.
For examples of how to use LINQ to Twitter, open the LinqToTwitterDemo project and view the Program.cs file. Uncomment the method call in the Main method for any of the samples you would like to run. Remember to change parameters as needed for the code to run on your system. i.e. The upload image methods will require a file path to an image that resides on your system.
I hope you enjoy using LINQ to Twitter and would like to hear from you on any projects that you've used LINQ to Twitter with. Good luck, keep in touch, and I'll be watching for your tweets.Joe