C# file sharing program

Need an easy to use application that automatically sets up a file sharing sharing session between a number of wireless computers. The goal of this application is to overcome the difficulties of setting up a ad-hoc network for file sharing. Any method is acceptable - automatically setting up a ad-hoc network in windows, or rolling your own system. Needs to have a friendly, easy to use, simply interface. An user that wants to join the session only needs to type in a password to join. Then a user can drag and drop a file from his computer to the app.(all files contributed by all users displayed in app, file along with contributor name, contributor can revoke share.) Then another user can drag and drop the file from the app to his computer. Needs to be super reliable, redundant, and fool-proof. so that anyone can easily use the program.