In 2-quart saucepan, heat water, gingerroot and sugar to boiling over high heat, stirring to dissolve sugar. Reduce heat. Cover; simmer 5 minutes. Add tea bags; remove from heat. Cover; let steep 15 minutes.
Remove tea bags. Cool tea to room temperature, about 10 minutes. Pour through strainer into clean 2-quart pitcher to strain. Refrigerate at least 2 hours until chilled.
Just before serving, add sparkling water and ice cubes to pitcher. Garnish with lemon, lime and/or orange slices.