Lost in million tabs? Use TabSense.
TabSense shows your tabs in a vertical hierarchical tree structure. By clicking on "All Windows" you can see all the tabs spread across all windows in one view. You can reorganize them by moving them around with drag-n-drop. You can save a window in TabSense, so that it gets closed and frees some resources, but its tabs can be retrieved in future by opening the saved window from TabSense.
[Inspired by Firefox's fabulous Tab Candy concept]
This extension is open source.
For bugs and feature requests: http://github.com/jyro2080/TabSense/issues
Developer contact: @jyro on Twitter, http://www.altcanvas.com