Boriss recently jump-started the discussion about tab management with her recent great post — if you're interested in how we deal with tabs, I encourage you to go read it and join the discussion. She deals with the issues of finding the tab you want in the sea of those you don't, as well as mechanisms for organizing tabs around real tasks.
I think it's worth coming at this problem from the other direction as well, crushing it, finally, in something we like to call the pincing crab-claw of good design. Implicit in the question of "how do we help people manage tabs?" is the assumption that people want to or should have to manage their tabs; this is definitely true for some tabs, but I think that fully half of the solution will come through helping people avoid a situation that requires capital-M Management in the first place.
Sometimes people have multiple tabs quite simply because they need to have multiple documents or applications open simultaneously. But sometimes tabs are stand-ins for activities that could be supported (better, even) in some other way.
One way to deal with this this is by getting web apps out of the browser and into their own independent windows, as in Prism. By handing the window navigation task from the tab strip to the OS, we let users make use of the often richer and certainly more familiar set of window navigation tools available there (alt/cmd-tab, expose, taskbars/docks, and so on). Even working almost entirely within a browser as I do, I still find myself quite often hitting Cmd-tab (on the mac) to get back to my email, which is, of course, just in another tab rather than another application. This doesn't make as much sense for transient documents, but for something long running like an application, this can be very powerful.
What can we do to support the "deal with this later" use-case that doesn't contribute to tab-clutter? I've started tagging pages to come back to with the tag "queue" and then, periodically, looking at everything with that tag. It's not an ideal solution, though, because I still have to initiate the reminder process. It helps to remind of what I have to do, when I think to check, but not that I have to do something.
Quite often, when I try to sift through and clean up my tab pile, I find that I have the same document open in multiple tabs. In part, this is because it's getting easier to navigate to a page again than to find one that I know is already open (which better tab navigation will start to reverse). But in many cases, I'm sure I just didn't remember that I'd opened something previously. Making it easier for people to re-use an already open tab would certainly help prevent the tragedy of tab-inundation.
One early concept for this is an attempt to intercede when we see tab duplication beginning — as a user begins to tell the browser where to go. Some quick idea sketching led me to some variants on putting this information in the awesomebar - more discussion of these in a future post:
Lastly, some open tabs are documents that you're well and truly done with, but that you didn't close. Metaphorically speaking, you just left it on the floor and walked away, again. Would it kill you to tidy up after yourself?
Amidst the sea of open tabs, though, it takes effort to comb through your tab list for the flotsam and jetsam. To paraphrase something I read somewhere recently, there's immediate benefit to opening a tab but not for closing one. The benefit in the latter case is separated in time from the effort to get it — this is a contributing factor for all clutter, really.
What can we do to encourage or make it easier for people to close tabs that they're finished with? Some add-ons try to lower the effort bar on the triage, by providing an indication of tab age and disuse, for example. What else can we do here?
If you have thoughts or suggestions about these issues, please do get in touch! Other good sources for insightful thinking about the nature of tabs and their management are Aza and Bryan. Update: Andy Edmonds has also written on this topic.