Obviously this technique won't work in every conceivable situation... you all will have to be clever with when and where to use the holodeck effect. I'm not sure how it will work if there's a battle going on around you.
I could try the effect you saw in City on the Edge of Never, but I'm afraid it wouldn't look very good in this case. It would literally be a flat texture with no changing perspective or depth, and you would be able to walk right into it. With the Guardian, at least it was kind of a whispy flash of random images, but this would be a constant unchanging picture of a hallway.
In other news, I figured out how to get the Holodeck objects to NOT show up on the minimap, so yay for that
Also, I'm starting some discussions with the Foundry programmers for how we can set up better safeguards for teams so some team members don't get left behind when triggers are used to trap the player.
Speaking of the minimap... any chance we can see higher resolutions here? I remember one episode in the Breen series had a far more detailed minimap that put the rest in the game to shame.