Pink gin and water is also nice. 2 or 3 drops added to a ginger beer is one of my favourite very, very low alcohol drinks. Oh, and one of the several versions of rock shandy is 50/50 ginger ale and soda water, with a few drops of bitters. A bit of searching and I've found culinary uses at this site
[Simons Mith] When I was a student, one of the drinks of choice at the time was a long vodka which consisted of a few drops of bitters smeared round a highball glass, ice, a shot of vodka, a dash of lime and topped up with soda water. A bit girly but very drinkable.