[yamtaddle]

Yeah immediately thought of StumbleUpon.

Incidentally, this is one of several things I've thought FF should have integrated into the browser to differentiate themselves and maybe retain or, if you can imagine it, grow their userbase. It'd be an outstanding core of a distributed social network, if they wanted to take it that direction, and a decade or so ago FF was uniquely positioned to make such a thing happen by integrating it directly with the browser so the best way to experience it was in FF. These days, I'm not sure they've got enough users left to make such a play, but they did at one time.