I think Nuun tastes great. It is a slightly fizzy drink with a very mild flavor of your choice. I like the fruit punch, strawberry/lemonade, and tri-berry myself. If I think I might want a Nuun or a Crystal Light drink for lunch or at the end of the day, I'll take a dedicated 16 oz. wide mouth aluminum beer bottle (1.0 oz.). I don't want my regular water to have a taste. The Nuun tablets are an inch in diameter, so the wide mouth accomodates them. The tablets are scored though, so they can be easily broken and popped into a regular PET bottle. Nuun has no carbs, just simple electrolytes, including potassium.
The real thing is, for short trips, do we really even need to do electrolyte supplements? The food we eat will likely replenish things for a trip of a few days duration.
Having said that, I have been in a few situations where I felt the need to preventively pound down the water and Gator Ade all day long (a liter of something, usually just water, or half-and-half, every hour). I have deployed with a Federal disaster medical response team to several hurricanes, working in the direct sun in humidity and 100* F temperatures for 6-10 hours at a time (wearing dark blue uniforms!). There were very few cases of a teammate having electrolyte issues, but plenty that became dehydrated in varying degrees of severity. Drink, drink, drink!
Keep in mind that the body doesn't rehydrate very fast. Once you get into fluid debt, it's nearly impossible to get back to normal quickly. The key is to become fully hydrated 24 hours before you start exerting, and then sip a few ounces of water every 15 minutes while you sweat it out on the trail. Chugging a full liter at a time doesn't really work, physiologically, because the stomach can only absorb it so fast. But maybe it saves on stopping so often, since the water sits in your stomach while it waits to be absorbed, rather than in your bottle. One other thing I've learned about heat and dehydration while on deployment, and while living in Saudi Arabia, is to get out of the sun at every opportunity. Deserts don't offer much shade, but take advantage of the ones that do present themselves.
I hope the desert hikers will chime in and lend their expertise on this topic.