Last week I noticed the release of a nice Team Explorer extension, the Build Explorer. This tool allows you to organize your build definitions in a very simple way. By following a specific naming convention for build definitions parts of the name are presented as folders.
So, for instance, a build definition called ALM.TFS.Gated would be rendered as:
The “.” is a separator character (and is configurable, of course). The source code are published at http://tfsbuildfolders.codeplex.com.