Web API 2.1 brings a lot of great new features to the table. One of them is global error handling, allowing you to log all unhandled exceptions through one central mechanism
This is a sample from the Web Api documentation:
The annoying thing I noticed is that the IExceptionLogger interface is not resolved through the dependency injection integration mechanism that Web API offers out-of-the-box. So you explicitly have to register your implementation through the Services property on the HttpConfiguration object.
Hopefully the Web API team will change this in the future...