How To Accept a File POST

I’m using asp.net mvc 4 webapi beta to build a rest service. I need to be able to accept POSTed images/files from client applications. Is this possible using the webapi? Below is how action I am currently using. Does anyone know of an example how this should work?

[HttpPost]
public string ProfileImagePost(HttpPostedFile profileImage)
{
    string[] extensions = { ".jpg", ".jpeg", ".gif", ".bmp", ".png" };
    if (!extensions.Any(x => x.Equals(Path.GetExtension(profileImage.FileName.ToLower()), StringComparison.OrdinalIgnoreCase)))
    {
        throw new HttpResponseException("Invalid file type.", HttpStatusCode.BadRequest);
    }

    // Other code goes here

    return "/path/to/image.png";
}