I was thinking about the problem with future divinations in a game is that it is hard to make them actually useful. Players are pretty unpredictable that even a GM can't say what will happen with any good authority.
However, there's a neat way to handle this in the Fate system. Do a Divination Ritual of 8 or so complexity, that's about right to place a maneuver on you for a day (that assumes a "scene" is 15 minutes, the default duration of a maneuver). The aspect is "Prepared for the Future" or somesuch. While you can boringly invoke this for a +2 to a roll, you can Invoke For Effect for some interesting stuff such as a complete justification for having an odd potion you otherwise couldn't justify (remember while you can declare you happen to have a potion on you, the GM can also decide it is just too unlikely, and this gets around that). You could also Invoke For Effect to say you weren't surprised by an ambush or any number of other things (e.g. you happen to be carrying a self-inflating boat when you get tossed overboard into choppy waters). The beauty of this is that it preserves the surprise for the player and in-game it doesn't break the 6th Law since you can't actually affect the time-stream to a meaningful degree (imho, the "light touch" is preserved). Essentially it just makes you able to create super-coincidences.
