User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b10pre) Gecko/20110114 Firefox/4.0b10pre Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b10pre) Gecko/20110114 Firefox/4.0b10pre I use multiple tabs and multiple windows. One window will often be on a different virtual desktop than another, and will contain different sets of tabs or tab groups. But sometimes, I need to move a tab or group of tabs from one window to another. While you can drag single tabs around, dragging groups is not possible right now. An easy way to assign tab groups to one or more windows would be extremely useful. This would work much like Spaces on the Mac. Each tab group should optionally appear in the current window, in a different window (move group), or in all windows. Note that this approach saves memory by allowing tabs that should be universally accessible to be accessed from any window. For example, web based applications like gmail and Pandora would be much more useful if they were always available in your current window. Conversely, tabs related to specific projects might have little benefit if displayed in other windows. Implementation of this feature on the tab level would also be extremely useful. Reproducible: Always Steps to Reproduce: 1. Try to drag tabs or tab groups from Panorama in one window to Panorama in another Actual Results: Doesn't work. Expected Results: Tabs and tab groups can be reassigned to other (or all) browser windows, thus making it very easy to access specific groups of tabs regardless of which window you are using.