I'm looking for some Firefox (4 or 5) extension to save a group of tabs (better if can be done directly in Panorama view). What I mean by "Save tabs" is not to restore them when Firefox starts.

I always have the browser opened and a LOT of tabs (work and personal life related) eating my RAM. So when I'm not working, I would want a way to save those tabs but keep them closed while I still use Firefox. So when I have to start working again, I will restore that saved tabs back again.

I know I could use something like Read It Later, but I really need a way to say "hey, save this group of tabs and close them". RIL makes me do it per tab, which is annoying since I'm used to have A LOT.