Our family room is separated from the kitchen by two steps down on one
side of the room, and by a banister railing the rest of the width of the
room.  A recent furniture re-arrangement has left the railing clear on
the kitchen side, and on both sides near the steps.  The space between
the rails is plenty large enough to admit a cat, and the
energy-efficient* felines of the household regularly pass between rooms
by that means instead of walking ALL THE WAY OVER TO THE STAIRS (phew).

The railings and the opening have proven irresistable to a certain 1
year old baby, so DH and I ordered a clear rigid vinyl barrier that
attaches to the rails and prevents the way-ward toddler from getting
stuck or worse.  I installed it yesterday.

Well, last night, Mithu was comfortably ensconced under my desk (on the
family room side) when Fizzgig (on the kitchen side) spotted him.
Feeling frisky, Fizz crept up to pounce on Mithu from above, and ran
head-first into the force field. He shook it off admirably, but I'm
pretty sure I saw Mithu smirking...

Cheers,
Caroline S.

* energy efficient == lazy