Get the Directory and Page Name

If you need to find the aspx page name (including the folder it's in, if applicable) use the AppRelativeCurrentExecutionFilePath property of the Http Request:
string filename=HttpContext.Current.Request.AppRelativeCurrentExecutionFilePath;
This will return results like: ~/MyFolder/My.aspx   or ~/MyRootLevel.aspx

I found this at: http://www.west-wind.com/weblog/posts/132081.aspx