Soldato
http://research.microsoft.com/vibe/groupbar.aspx
This looks like it could be useful for multi-monitor users especially.
GroupBar is lightweight desktop tool created by the VIBE group that offers enhanced window management capabilities in a Windows taskbar-like setting. The basic concept is that through simple drag-and-drop operations on window tiles within the bar, users can create lightweight, transient grouping relationships that allow them to perform certain higher-level window layout functions on multiple windows at once. In addition, windows and groups in the GroupBar can be persisted in a "Snapshot" which attempts to remember the position and contents of each window in a way that allows the Snapshot to be recreated at a later time, even if the windows have been rearranged or closed.
This looks like it could be useful for multi-monitor users especially.