Binaries for VS 2005, 2008.
Debug visualizer for SPList objects.
For VS2005 extract
SPDV 0.6 binaries 2005 to <My Documents>\Visual Studio 2005\Visualizers directory if you would like to be available just for current user or to the %VSINSTALLDIR%\Common7\Packages\Debugger\Visualizers to be available to all users.
For VS2008 extract
SPDV 0.6 binaries 2008 to <My Documents>\Visual Studio 2008\Visualizers.
Start debugging, the debug visualizer should be available for any SPList object:

click on the magnify icon to display the visualizer:

The visualizer will display the list name, list GUID, it's folders and items (if available) in a master-detail relation.
This code is not optimized for and has not been tested with large numbers of folders and items. Even if the list contains few folders/ items, the visualizer will still take some time to load.
Debug Visualizer for SPWeb hierarchy has been added:

Other debug visualizers: for SPFieldCollection and for SPRoleAssignmentCollection.