We have a lot of test tools we use around the OneNote test team. Some are available to everyone (everything from Sysinternals or Fiddler, for instance) and some we create ourselves. For these tools, we check in the source code into our code repository so we can all reference it or make updates when needed. A much larger win for some of these tools is simply having the code around in case of a hardware failure. I've lost some of my own data when hard drives have gone out on me, and having a back up system is always nice.
One of the other types of code I've started checking into our repository is the source code for my powertoys. I've kicked around the idea of putting these on www.codeplex.com at one point. That site is aimed more for projects that are ongoing rather than one-off "proof of concept" type of addins I write, so that is not an ideal place.
I finally decided to put them into our test code repository since we can use these to test future versions of OneNote as well. I also like the versioning I get. When I added the code to import images to my text importer, I had to make a few attempts to get it right. In each case, I created a copy of the text importer and pasted my new code into it. This works for small projects, but the larger the code base (more than one source file) the less this manual copy/paste works. Sometimes you just want to roll back two or three changes and I can do this now.
So I am on a push to round up the code for my addins so I can have it in one central place. There is even the benefit of being able to use these addins to test OneNote and future compatibility, so this is a nice little "win-win" project to complete.
Questions, comments, concerns and criticisms always welcome,