The com component will quickly tell you how much disk space a folder is taking up, this also includes subfolders under the root folder, ideal for web sites that serve document/image content.
Example .asp code included

simple ASP example of usage:-

Set Obj = Server.CreateObject("GETFOLDERSIZE.GetSize.1")
dim sz, files, folders
sz = Obj.GetSize("c:\inetpub\" )
files = Obj.files
folders = Obj.folders