3 oz. Beefeater's 24 gin
3 oz. V8 Fruit Medley
3 oz. Diet Mountain Dew
Let it gravity stir by pouring and then leaving it sit for five minutes.
I call it a "Slender Billy" after William II, one-time Prince of Orange and eventually King of the Netherlands, wounded as a lieutenant-general on the Allied side at the Battle of Waterloo.
This is the first mixed drink I've figured out which works with gin other than a gimlet. I can't stand martinis, gin-and-tonics, and most other gin-based cocktails, so at least it gives me a reason to bother with gin on my booze shelf other than... completeness.