I was thinking of out-of-combat uses for the Child of Shadow stance (I'm guessing that out of combat it would grant concealment as long as the user is moving + a bit after), but I don't know if there are any concete rulings for concealment out of combat, such as enemies having to do a Spot check or not seeing the character, or if there is an augment in the DC to see the character or if it's entirely up to the DM how to apply that.
If you move at least 10 feet during your turn, you gain concealment against all melee and ranged attacks until the start of your next turn.
Well, if you wanted to be super-literal about it, activate this ability on the last turn of combat and move at least 10 feet. It will then last until the first turn of your next combat since it lasts until the start of a turn, not the end of a turn :-)
On a more-serious note, stances are active until replaced or deactivated. Additionally, it can be calculated how much you move out-of-combat over a given period of time. Therefore, as long as your character is moving at the appropriate speed (10'/rnd), it should be easy to calculate if you are benefiting from concealment.
Note, though, that this stance does not affect your visibility from a "hide" perspective in the slightest. It actually points out in the skill description that the concealment granted by this skill cannot be used to make a hide check. All this skill does is makes you look blurry so that ranged and melee attacks against you will suffer a 20% miss chance, but you are still visible. Also note the difference between concealment and total concealment.