Vodka tonics are frequently garnished with a slice of lime or lemon.
One commonly used recipe is one part vodka and one part tonic water in a tumbler, often a highball glass over ice, with a generous lime wedge squeezed into it.
[1][dead link] The drink is referenced in the lyrics of the song "Goodbye Yellow Brick Road" by Elton John.
[2] The drink is referenced in the book From Russia with Love by Ian Fleming.
In chapter 17, second paragraph Bond sips a vodka and tonic whilst watching the sunset over the Golden Horn in Istanbul.