Creating Add-ins for Visual Studio 2005 using C#
Ever wanted to create an add-in for Visual Studio? Well, this KB article walks you through the process of creating a simple add-in that inserts the current date and time at the insertion point in the editor. You can expand on this to create your own custom add-ins that do even cooler stuff, like insert "Hello, World!" (ok, I'm kidding about the Hello, World part. I'm sure you can come up with something MUCH cooler than that).