I've personally had my justice points at a cap for roughly a week now, just waiting for 4.1 to drop so I can snag some maelstroms, but in the meantime I'm still earning more JP and I don't want them to go to waste so I looked around and thought of things I could buy with my JP that would be worthwhile.
I gave it some good thought before I came up with the idea of turning in some of my JP for primordial saronites. You read correct, that old crappy stuff that still goes for 100-200g at the AH still sells constantly. I've managed to snag 10 in the past week or so and I've sold them all for about 150g per.
Check out this graph that outlines the prices of primordial saronite across all US realms:
So if you have some spare JP or you're JP is capped, spend some on primordials to make sure that your daily heroic isn't wasted.
P.S. A recording of last nights meeting will be posted later today as me/we're having some issues with it. Check back later today. Sorry folks!