OpenTF is an open source (BSD licensed) implementation of the Team Foundation assemblies and TF client which may actually be better than the base TF PowerTool
Visual Studio Team System 2008 Team Foundation Server Power Tools is a set of enhancements, tools and command-line utilities that improve the Team Foundation Server user experience.
"Version 2.2 of Team Foundation Sidekicks includes Permission Sidekick, Code Review Sidekick, Shelveset Sidekick, Labels Sidekick, History Sidekick, Workspace Sidekick and Status Sidekick in uniform GUI stand-alone application, and Visual Studio Integraton Package providing VS integration for all sidekicks as well as additional features such as Search Items dialog, dynamic History and Build Type editing support. "