TidyTabs - TidyTabs brings tabbed browsing to all of your desktop applications.
Auto Tab Discard - Auto Tab Discard a lightweight extension that uses the native method (tabs.
BrightExplorer - Add a tabbed interface to Windows Explorer.
Firemin - Firemin will force Firefox to use less memory. It is safe to use, spyware free and completely free.
TabExplorer - Download TabExplorer - A simple-to-use yet powerful software tool that helps you make your Windows Explorer look like a tabbed browser, while offering support for preset tab colors
Dormancy - Dormancy 'retires' tabs that have gone unused for a while, freeing up that memory.