Errr... if you have got to where you say then you usually have all the vaults shown on the map by now.
Go exploring dude... don't just do the core missions. Exploring finds a whole HOST of other side stories like cannibals and zombie chinese soldiers etc...
Where there is a big area on your map without anything marked down, just go there... don't get the skill that marks everything on the map because then you don't know where you have been btw.
But yeah.... exploring in F3 is the way to go... You find loads of cool weapons and stuff doing that too.
Exactly, if you have Mass Effect its kinda like that, just go everywhere there are so many side quests its unbelievable.