How to make a mirror in the editor??

[FlawlessHappiness]

Just made this:
http://www.youtube.com/watch?v=f-UZ9mt9Izs

It's a water material - no cubemap. Some weird things happen. Performance-wise it's not advisable, go for a cubemap if possible. It's "real time" reflection though!

That's brilliant! I'm guessing there are certain stuff that does not exactly work in the mirror.
Just like particle-effects that doesn't know it's on the surface of the water, and therefore shows itself as if it was underneath it.
Did you look at the objects that moved weird?