This is my current favorite summer beverage.
When the temperature soars to at least 100 degrees (85 for all ya'll Midwesterners), stick a glass in the freezer for a few minutes. Then add:
2 slices of lime plus a couple squeezes of juice to taste
2 teaspoons of sugar
2 teaspoons of fresh lemon juice
A bunch of fresh mint leaves
Crush everything together with a wooden spoon, an ice cream scoop, or a fancy muddler, if you're feeling fancy.
Add about a quarter cup of white rum.
Top with club soda to taste.
Fill glass with ice.
Sip on the patio and wait for December (September if you're a Midwesterner - see, I may not have any trees where I live now, but I remember my roots)