I've pushed this idea in other MMO forums - but yet to see it implemented.

I assume FO will have some sort of standard quest system (the guys with the ! over their heads). For your average semi-conscious player, those are fine and should make up the majority of the game. But... I'm a big fan of secrets and rewarding those that pay extra-close attention to the lore and detail in the game.

Those random NPCs that seem to spout cycled audio as they trudge about town... what if those bits sometimes had a meaning?

The results wouldn't necessarily appear in any quest log (other than one you might keep on your own) - but could essetially progress as normal quests... leading players to perform certain emotes/activities... opening up new content.

Of course, the difficulty and frequency of these quests/clues could vary. Some obvious ones(a drunk at a bar muttering the password to a local club he couldn't remember earlier) in the starter areas to introduce players to the new type of gaming... others that are infrequent, complex, and hard to solve... the big mysteries of the game... (how do you open that sealed vault!?!?!?).

that's a good idea for single player games, unfortunately secrets in MMO games tend to be well known faster than secrets in desperate housewives In gaming terms... Life's a die, then you bich.