Thank you! I am picturing it to be a round structure that would be partly hollow to house the ashes. The interior I picture to be LED screens so the images and messages can be displayed. Something like this: http://pixelflexled.com/products/outdoor-led/#curve
On the outside it could be a reflective metal surface that can be engraved with the people's names that are resting there. The engraving would be optional. The reflective surface is so that the people are able to see themselves in the memorial, so they become part of it and with everyone that is resting inside. Since the One Memorial is a symbol of unity and equality under all humankind.
As for it getting built, I don't know about the logistics just yet. It could be a city initiative to help relief the overcrowding cemeteries or via investors or on donation basis. Since a social network is connected to it, it could also be funded via advertising space on that network. Businesses that are related to funerals, insurance and the like could buy advertising space, which could finance the upkeep of the memorial.
Please let me know if you have any more questions. Thank you!
Yes, any major open-minded city in the world I think would be able to do something like this. Berlin, London, Sydney... I saw your other comment in my email, and yes, the experience would be personalized. We now have the technology to recognize someone via their cell phone. So once they enter the memorial their pictures and messages would appear on the screens, if they are connected with the social network that goes with this.