You don't even have to go as far as Hawaii to enjoy tropical flora. New Orleans is a sub-tropical zone and is absolutely rife with enormous hibiscus, bougainvillea, birds-of-paradise, and even has wild parrots in City Park. Plus NOLA still needs help recovering from Katrina.

Your advice is good, but I think it depends on where you live. I decided to plant some cacti and succulents right in front of my house, but we've had so much rain lately that they aren't doing too well. They haven't died, but they also haven't grown much at all. I live right outside of Houston, and I have three hibiscus bushes that are as tall as my house. They bloom continuously throughout the year, and I never water them. We have a pretty nice front lawn, and we water it for just a few minutes once or twice a week. I've also found that a lot of plants that are labeled "annuals," like impatiens, begonia, etc. survive the winters here and comes back in the spring even bigger and prettier than the year before. "Drought tolerant" isn't necessarily the best practice for everyone, though I do think it just makes sense to plant what grows well in your native environment.

Planting locally-appropriate is much more effective than broad-brushed advice like "use drought-tolerant plants, avoid annuals." In the Pacific Northwest, plants have to be able to handle a fair amount of rain as well as some summer dryness. Spring annuals around here do just fine with no added water, finishing their cycle before the dryer weather hits in July. Some parts of my yard grow moss year 'round--no drought-tolerant plants are needed there!
Also, ATnest would do well to keep spin in mind--many people still think of drought-tolerant landscaping as sere and bland, something to do because it's good for conservation rather than having any aesthetic appeal. Remind people of how gorgeous sustainable landscaping can be! (hint: a picture is worth a thousand words)

Native plants tend to be most appropriate for any given climate. I don't water unless I have an area of newly planted perennials, the babies get water the first year as needed but after that... they go free of the hose and other fussy care. My lawn tends to brown out each August with hot dry weather but recovers by mid Sept. when the rains return. The make up of extensive perennial beds has changed over the years as some varieties die out and others self sow or spread on runners. I try to keep a nice aesthetic balance by relocating volunteer plants to more appropriate locations. Mulch keeps weeds away and maintains a more even moisture content.

ITA with previous posters that it depends on the rain-fall where you live but want to add that it also can depend on soil type. Where I live now, the soil is sandy and water drains away quickly. Even though we get a good amount of rain, drought hardy plants are called for. I grew up in an area with a lot of clay soil. Moderate rainfall produced mud and standing water, and a different variety of plants thrived there even thought the hardiness zones are similar.

I'm like Alice...I water plants (and maybe fertilize) through the first year and they are on their own after that. If they survive, great...if they don't, I try another species.