Ok, here's my list of possible horcruxes:

PS: Wand displayed at Ollivander's - Ravenclaw horcrux
CoS: Diary - Destroyed
PoA: ??? - Gryffindor horcrux
GoF: Voldemort - Alive and well by all accounts
OotP: Locket - Slythering horcrux
HBP: Ring - Destroyed
HP7: Cup - Hufflepuff

Here's the deal, I just read Lori Summer's "Paradigm of Uncertianty" for the first time and there's a certain mechanism that involves tarot cards (not to completely spoil it for you if you haven't had a chance to read it yet) and for some reason that tripped something in my brain relating to horcruxes (possibly the mention of the King of Cups).

So here it is in shorthand:

House Horcrux	Tarot suit
Wand at Ollivanders	Wands
???	Swords
Locket	Pentacles
Cup	Cups

It's that last one that confuses me.  We've seen Gryffindor's sword but only in CoS.  To my imagination, there is abosolutely no way that's it's a horcrux.  I'm wondering if someone managed to fool Tom Riddle with a fake but that's almost as unlikely as the first possibility.  I wonder if there is a sword lying around inconspicuously in PoA?  Hmm....  Of course, it doesn't altogether rule out Harry's scar which seems to be a fan favorite....

I also noticed something else that relates to my observation of the Gryffindor/Ravenclaw connection in relationship.  The most notable ones are Bill/Fleur, Hagrid/Maxime, Ron/Luna *cough*, and Harry/Hermione *cough* *cough*.  Here goes: Gryffindor = fire sword = air,  Ravenclaw = air wand = fire.  And then there's Slytherin = water Pentacles = earth, Hufflepuff = earth Cup = water

Can anyone explain why I'm seeing this pattern?