Win7 Library Tool
Windows 7 libraries are a really useful feature of Windows 7, however unfortunately they arrive in a slighly cut-down form out of the box. Microsoft decided against exposing some really useful capabilities to users, like adding network locations, pretty much the first thing I tried to do. You get this message:

Luckily, you can add network locations (and any other un-indexed locations), but it must be done programatically. MS supply a command line utility slutil.exe, candidate for the worst named executable in history. Pretty sure it stands for shell_library_util. Anyway, I decided to write a tool to make it easy to add network locations, and added a few other features as well:
- Add network (UNC or mapped drive) and any other un-indexed folders to libraries.
- Backup library configuration, such that a saved set of libraries can be instantly restored at any point (like after a re-install of the OS or for transfer between multiple computers).
- Create a mirror of all libraries (using symbolic links) in [SystemDrive]:\libraries. This means you can reference all your files using a much shorter path, and also provides another entry-point to your files in many places in the Operating System (e.g. file open/save dialogs).
- Change a library’s icon.

Hopefully it’s easy enough to use, so I don’t have to explain it
You can download it for free below. (Note: This will only run on >= Windows 7.)
Download Installer | Source Code
I must give credit to Josh Smith for his TreeView CodeProject article, upon which this solution is modelled.
The application uses the Microsoft API CodePack to manipulate libraries, which I encourage you to check out if you are writing software to integrate / take advantage of new features in Windows 7.
If you want to learn why and how libraries were introduced in Windows 7, including diving into the .library-ms file format, you can read this MSDN article.
Now featured on Tekzilla!
I found a small but annoying bug for users of foreign language Windows 7 users: Sometimes the librarary tool changes the dutch word ‘Afbeeldingen’ (the dutch name of one of the default library’s) in ‘Pictures’ (the english translation with the same meaning). Windows does not recognize the english term ‘Pictures’ and the library is ‘lost’ (for Windows, but the keen library tool recognizes it perfectly). When I change the name ‘Pictures’ back in ‘Afbeeldingen’ (dutch) , possible only in Win7 library tool, everything functions normal again. I have my bug fixed, but can you fix your bug? (Hard to find in the English version of Windows). It’s strange the library ‘Documents’ does not seem to suffer the same abbaration.