Lorem Ipsum

I keep thinking it would be great if browsers had a better tab-and-window management system.

I'm probably an atypical browser user: at any given time, I generally have about two dozen browser windows open, with one to ten tabs per window. Managing those tabs and windows is a big pain.

But I know I'm not entirely alone in this. I occasionally watch a colleague with twenty or thirty tabs in a window try to figure out which tab contains the document they want to switch to. And I suspect that Chrome OS is only going to make this kind of thing worse, with everything in browser tabs.

So here are some of the features I would like to have, based on problems that I run into while browsing:

• Ability to tag tabs (or URLs, or domains) with user-defined names that could be used to conceptually group them even if they're in different windows (see list view, below).
• This is probably the most important feature on this list, and the one that would resolve the largest number of my tab management issues: A list view of all open tabs, easily sortable in various ways: by window, alphabetically by title, by domain, by tag/grouping, by whether video and/or audio and/or Flash is currently running in the tab, by date the tab was last opened or last foregrounded, etc. Also with a type-to-search feature, so that if I wanted to quickly switch to a given tab, I could just go to list view and start typing its URL or title (or a word that appears in the page contents) and it would jump to that tab.
• Notification if you try to open a URL in a new tab or window that you've already got open in a different tab, giving you the option of switching to the one you've already got open or of opening in a new tab or window. (Perhaps there could be a user-editable list of URLs that this wouldn't apply to, like my Create New Blog Entry URL.) This would help me avoid having five different windows containing the same Google Doc, for example.
• Social buttons: easily tweet, FB-share, G+-share, or email the current tab, perhaps placing any selected text in your share message. (This isn't quite tab management, but it would improve my tab experience 'cause I wouldn't leave so many tabs sitting open waiting for me to get around to sharing them.)
• One-click button to pause all running video and audio in all tabs.
• Automated reminder in some form (maybe just as a flag icon in list view) for tabs that have been sitting around open and unused for a long time so you can opt to close them, archive them to a Reading List or other bookmarky-like thing, share them, etc.
• Quick side-by-side view: Indicate two tabs that you want to view together, press a keyboard shortcut, see the two next to each other (or slightly overlapping or something) on your screen. Press another keyboard shortcut to exit this view. No more dragging windows around to get them next to each other!
• Ability to name a tab group that can be reopened as a group. (I can do this in Safari's bookmark bar, but I never use that feature in its current form.)
• Better saving/history of open tabs on crash, and better options for restoring on relaunching the browser after a crash.
• Much better “reopen closed tab/window” features. Safari's Undo to reopen a just-closed tab is great, but it only works (I think) on tabs, not windows. Chrome's Recently Closed section of its History menu never works the way I want it to, though I haven't sat down to figure out exactly what's so weird about it.
• Context-menu ability to open a given link into a new tab in a specific window or tag. (So if I'm reading Google News and I see an article about privacy, I can open it in my Privacy Stuff window rather than first opening it and then having to drag it around.)
• Ability to restart browser (in order to deal with memory leaks) without having to actually reload all the open pages—just save the caches and current state, and restore those on restart. (But maybe restoring current state would restore the memory leaks, so maybe this wouldn't help? Not sure.)
• Would be great if several of the above features could apply to the Reading List (or corresponding feature in other browsers) as well (especially list view).

Some of these features exist in various contexts. For example, I use a Safari extension called Sessions that does one small piece of it, and I gather that OS X Lion's new Mission Control feature does some other pieces of it. (Haven't upgraded my main computer to Lion yet.) But I haven't seen most of this stuff done anywhere, and it would be hugely useful to me.

I'm sure there are lots and lots of other related features that would be cool too; the above is just a ten-minute off-top-of-head list.

What tab and window management features would you find useful? And what browser tools or extensions do you find helpful for managing tabs and windows?