Panorama exists for Firefox 4 and various tab management extensions available for Google Chrome, Tabs Saver simpler and productive extension for Chrome allows to save opened tabs in a window as a group and you can close/leave them and open new tabs and work with them in the current window, after your work is finished you can open saved group by with one click in same window.

Tabs Saver allows to save tabs in current window

After installing Tabs Saver extension, its icon appears on Chrome toolbar.

To save tabs in current window, click Tabs Saver icon and name the group.You can access each tab in the group by clicking edit button for that group

Tabs Saver