Night scene lighting

[Lev]

Im trying to find efficient ways to create a night-time look for one of our scenes (it is a closed room with a window). Some of my ideas so far are
1) using advanced lighting override + radiosity for the window material and use the window as a light source.
2) Using a 3 point blue-tinted light setup
3) rendering scene with standard (daytime) lighting setup, and then add a blue-to-black gradient map in Photoshop

Any other ideas?