No, it's not on vDip. I've talked about porting it some years back, but as with most of my ideas, it's too intrusive to easily code.
The key idea comes from the 'fog of war' concept. Unlike the FoW variant, crystall ball limits your knowledge not by geography but by time. As leader of a power, you do NOT have real time info about any troops, not even your own. Instead, your info (in this case the map) is only known one phase after you sent it. Effectively, this means a horrible lag in your orders, which you have to account for in your orders.
Details here:
http://www.diplom.org/Online/variants/crystalball.html
I played it on the DPJudge ages ago, but there werent enough players that kept games live. If there are interested parties here, then I'm definitely up for a game.