Here's a couple of registry options that never made it into the UI anywhere that some of you may find useful.
Don't Automatically Reconnect
The first is a setting to control whether or not the Team Explorer and Source Control Explorer will automatically connect to a Team Foundation Server when Visual Studio starts up. This can be very handy if you need to restart VS often when doing add-in and package development and testing as well as situations where you are working offline.
Add a DWORD value called "AutoLoadServer" under HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\TeamFoundation. Zero means do not reconnect automatically.
Don't Automatically Get Missing Files
The next setting is to control whether or not we attempt to automatically get files from the Team Foundation Server that are missing from a solution or project. This can be very helpful when you have files that are part of a project or solution but are generated by the build process as well as situations where you are working offline.
Add a DWORD value called DisableGetMissingFiles under HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\TeamFoundation\SourceControl or HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\8.0\TeamFoundation\SourceControl. Any value other than zero will disable getting files from the server automatically.