TabCorral
No matter how awesome you may consider Firefox 4 you have to admit that its lack of tab groups is pretty frustrating especially since Opera introduced this feature quite some time ago. Even more Opera has a simply brilliant addon called TabVault but since we all know that of all browsers Firefox is the one and only tab king (at least when it comes to quantity...) TabCorral shouldn't come as a surprise. Anyway it's always great to discover awesome plugins no matter the browser they were built for so let's get to it! ;)
The short mumbo-jumbo regarding TabCorral goes like this: "With TabCorral you can save retrieve share and organize groups of tabs (called Corrals). Thumbnails provide views of tabs within a Corral for previewing. Corrals can be shared publicly and privately." On the other hand if you want to get a better view of the whole picture you should take a look at its official home here. Unfortunately you can't take advantage of all the goodies without creating a paid account and I think it's a real shame that there's no sync feature available to free users. :|
TabCorral 1.1.2 arrived yesterday on Mozilla.org so it's no surprise that it has no ratings yet only 18 downloads and it's still labeled as "Experimental" but it's also great to see that it seems to work with Firefox 1.5 - 4.0.* - at least until proven otherwise of course... but if I take a closer look at all you get from this Firefox addon I must conclude that despite its major drawback of not offering for free things that almost all other similar plugins/tools offer without charging a single penny TabCorral is worth checking out.
P.S. I am still playing with this piece of code so I see no point in giving you an overview of its features - if I say it's worth checking out then that is the truth the whole truth and nothing but the truth! ;)