For the quick ginger beer: In a large saucepan add the grated ginger (along with any juice), allspice berries, cloves, sugar and 2 cups water. Bring to a boil, stirring occasionally, then remove from the heat. Add the lime zest and let steep while it cools, about 30 minutes. Strain into a pitcher and stir in the lime juice. Fill with sparkling water. Serve over ice within one day or use in a dark and stormy cocktail. Makes 5 cups.
For the dark and stormy: Fill a highball glass halfway with crushed ice. Add the rum and 5 to 6 ounces ginger beer. Top with lime juice, stir and garnish with lime slices. Serve immediately.