Bon Appétit has a recipe in its April issue (not online, sorry) for Virginia bar PX’s Double R Daiquiri. At the bar, bartender/owner Todd Thrasher uses fresh rhubarb juice in the drink in addition to some citrus.
While juicing the rhubarb sounds like a hassle—they suggest puréeing it, sieving it, then squishing any remaining juice from the pulp by hand—I love the idea of using it fresh in a drink and leveraging its bitter/sour flavor, as opposed to making it into a syrup. (Though syrup has its own merits, like in our Touch of Evil cocktail or Knockout Punch recipe.)
It looks like I’m not alone. Apartment Therapy’s The Kitchn recently spotlighted a cocktail created by Franny’s in Brooklyn made with fresh rhubarb juice, Aperol, and vodka. And there’s a whole section of drink recipes at the rhubarb fetish site Savor-the-Rhubarb.com.