In a small saucepan over medium heat, bring the rhubarb, water and sugar to a boil. Reduce heat; simmer, uncovered, for 3-5 minutes or until rhubarb is tender. Remove from the heat; stir in gelatin until dissolved. Add the strawberries, orange juice and zest.
Divide between two 4-in. mini fluted pans coated with cooking spray; refrigerate for 4 hours or until firm. Just before serving, invert molds onto serving plates; garnish with whipped cream if desired.