Introducing Tab Star
Available at Chrome Web Store.
Star important tabs, and close all unstarred tabs with just a keypress, like a boss.
Instructions: Click the little star to star a tab. When pressing Ctrl+Shift+X (Cmd+Shift+X for Mac users), all unstarred tabs will be closed.
Why is this useful? Because you can keep the important tabs on, like Google Calendar and Gmail, and the results you want to keep for later use when doing a research. You may open up more than 20 tabs and decide to keep only 3 of them for later. Star them, and cleanup all the mess like a boss. Remember to unstar a tab when you’re done with it!