It's funny, before entering this thread I saw gin and tonic and I said refreshing. You said the same. It is a light and refreshing drink.
For the summer my gfs have always enjoyed blender drinks, particularly strawberry daqauris. I'll toss frozen concentrated lemonade in a blender with either strawberries, peaches, or bananas and give them a whirl with some crushed ice. I don't make proper daquaris, instead I use vodka rather than rum 90% of the time. It's cheaper and works great.
Frozen daquaris are great when your camped on a river or lake and sunning and swimming all day. I have a 12 VDC blender that plugs into my cars cigarette lighter so that I can make these when camping. I've seen some pretty interesting hand crank blenders recently, but I don't know how well they work. Of course it's summer for you guys, going into winter for us.