Such a useful extension that I just had to big it up – the Go Offline extension adds the following menu item:
File>Source Control>Go Offline
http://visualstudiogallery.msdn.microsoft.com/425f09d8-d070-4ab1-84c1-68fa326190f4?SRC=Home
If you use TFS in a big environment, sometimes this can save a stack of time. Thanks to Bernhard Tschirren for taking the time to write this and share it!