Today, I noticed that my first ever contribution to an open source project has been published. I had been working closely with Mike Fourie, who has been heavily involved with the MSBuild Extension pack. It's a library with a number of tasks that you can use in your MSBuild project, so that you don't have to re-invent the wheel. The tasks include commonly used functionality like managing folders, giving access rights to users, managing COM Plus applications, etc.
I use this library a lot in our project. I recently wrote some new functionality to concatenate strings in an MSBUIlD string. This got published in early April and Mike has kindly mentioned my name there :) http://msbuildextensionpack.codeplex.com/SourceControl/ListDownloadableCommits.aspx?ViewAll=true
More, I have also written functionality to create shortcut of installed files, so users can create links in desktop, start menu etc. It's not published as well.