Damn I wish my vanguard ira supported it today before it's too late.
The point of the OP is that you CAN do it today. You do not need to wait for Vanguard, Fidelity, or anyone else to support it. It just takes a modest effort and expense to set it up.
If there was a way to do it today then why hasn't anyone shared further details? I've put in more then a modest effort and I have not found how this would be done thru most traditional institutions.
What details would you like? The OP pretty much explained exactly what you need to do step by step. Its not easy, buts not overly difficult either with the right people involved. I googled IRA LLC and these guys popped up:
http://www.broadfinancial.com/self-directed-ira/ira-llcI don't know anything about them nor am I affiliated with them but they specialized in alternative IRA holdings. I use PENSCO personally.
Good luck!