Using shared C# source files between multiple Visual Studio.Net 2003 projects
Monday, May 15, 2006
The following article describes how to include an existing "common" .cs file in your Visual Studio.Net 2003 projects. "... right-click your project in Solutions Explorer, and select Add Existing Item. Browse to your shared C# source file, then click the unnoticeable little dropdown arrow next to the Open button. See the ctxmenu item entitled "Link File"? That's your man."
http://weblogs.asp.net/savanness/archive/2003/07/22/10417.aspx