A pair of short posts that show the "dynamic" keyword of C#4: http://www.codethinked.com/post/2008/10/28/C-40-New-Features-Part-1-dynamic-keyword.aspx http://www.codethinked.com/post/2008/10/28/C-40-New-Features-Part-11-dynamic-keyword-second-look.aspx Bye, bearophile