Remember the New Request and Response Objects

In ASP.NET, the Request and Response objects have been extended to provide many new features that can improve performance. For example, to write the contents of a disk file into a page, use the new Response.WriteFile method rather than opening the file, reading it from disk and writing it to the Response .

Finally, avoid the ServerVariables collection where possible by using the new Request properties like Request.Url , Request.Referrer , Request.PhysicalPath , Request.UserAgent , and so on.