Tabby is a Chrome extension inspired by a Tweet from Greg Leppert:
The chore of maintaining and pruning browser tabs & windows is flawed. I want neglected ones to slowly fade away, to sink back into the dirt— Greg Leppert (@leppert) May 8, 2011
As you browse, the tabs you leave unattended will be removed for you. You can control how long a tab will stay open and unattended before it is closed. You can also whitelist as many websites as you’d like.
Install Tabby Tabby on the Chrome Webstore Tabby on Github