1.   For nighttime privacy, use a roller shade or vertical blinds.

2.   If window-coverings are necessary, consider sheers, or one of the sheer new roller shades.

3.   Smith and Noble, a manufacturer of window shades, sells a roller shade that can be mounted inside the doorjamb.

4.   Trouble is, I cannot find roller shades without the shades, or even the hardware for such rollers so I could build my own.