Kind of annoying that you have to get involved in the different factions to find all the shouts. There is one that you can only get if you join the Companions, another that you can only get if you join the Thieves Guild, another that you can only find if you join the Dark Brotherhood....

I don't even know if it's possible to open up those particular dungeons to anyone who isn't going to do those quests.

Well you can get parts of the shout without joining the guilds =/

Extra incentive to do more, I guess?