Full sun or shade? How much work do you want to do to maintain it? I like podocarpus, but the kind I have needs mucho pruning to keep it four to six feet wide. Duranta repens is another choice. I'm not sure about your zone, though.

I have never had a dog that showed the least bit of interest in nandina. Have you tried to feed the berries to your dog to see what he/she does? The dog may just look at you like you are out of your mind. Then you could plant nandina if you wish.

There's a list of narrow hedge plants on the FAQ page here too.
Renee

Why not consider using a vine? Creeping fig, star jasmine, Burmese honeysuckle, beaumontia grandiflora could all fit into a contemporary style setting. The last three would need some means of support via attached wire/cables or freestanding or attached trellis. Some of the pittosporum tenuifolium cultivars would also work.

Boxwood 'Green Tower' is very nice: dense, neat, and narrow. Also not as slow as I thought they would be, mine are 6' after three years, trimmed back from 7'. (I only need a height of 6'). They are listed as about 9' in maturity. Boxwood is very "modern" in style.

For vines that cover block, I like Boston Ivy, Parthenocissus tricuspidata, though it is deciduous, and not tropicalissimo.

Thanks for the suggestions everyone! Keeping the "pseudo-tropical" and modern aesthetic in mind, I'll likely end up going with a clumping bamboo. The wall has a weird ledge around 4' up, so a vine would not work too well, unfortunately.

cheers!

GK