Here's something of a bonus - a bit shy of an actual drink, but a sufficiently impressive discovery to merit posting. Think of it as a sort of super-mixer; drink straight if you like, or just add booze for an awesome highball.
Another advantage is that this is completely scalable - make as much or as little as you like.
4 parts carbonated cucumber water
4 parts Q Tonic water
4 parts passionfruit juice
1 part lime juice
Combine and serve immediately, or bottle in a sealed container and store in the fridge.