Hm, yes, that could work.

Though it is still a bit too complicated because quite a lot of interaction is needed to do that, even with the delicious Firefox addon. You probably have to manually enter the group name as a tag, for example.

Ideally, I'd only have to click one button displaying a popup with all groups I've set up.

But well, sounds like the way to go - unless somebody can point me to something else.

So, thanks for your answer! :)