How to create context object accessible application-wide to store current user details in data access?

I have an n-tier web application with a Web UserInterface, BusinessLogicLayer and DataAccessLayer. I am looking for the best possible solution to pass my current logged in user's details all the way to the data-access without add it to all my method signatures. The user details are needed for auditing purposes. I believe you can create a context that is available application wide, is there anyone with an example of doing this? I am looking for the best design pattern that will separate my concerns.