Preheat oven to 350°F. Crush cereal in a food processor until it’s the consistency of breadcrumbs. Fiber One says you can do this step with a heavy duty plastic bag, but if you have a food processor it makes the job easier and you get a fine grind.
In medium bowl or in the bowl of the food processor, mix crust ingredients until blended. Press crust mixture evenly and firmly in bottom and up side of (well greased!) 9-inch glass pie plate. Bake 10 to 12 minutes or until firm. Cool completely, about 1 hour.
In a 1-quart saucepan, mix water and lime juice. Sprinkle gelatin on lime juice mixture; let stand 1 minute. Heat over low heat, stirring constantly, until gelatin is dissolved. Cool slightly, about 2 minutes.
In medium bowl, beat cream cheese with electric mixer on medium speed until smooth. Add yogurt and lime juice mixture; beat on medium speed until well blended. Fold in whipped topping and lime peel. At this point, do a taste test and see if you think it’s sweet enough. If not you may want to stir in a tablespoon of powdered sugar.
Spoon into crust. Refrigerate until set, about 2 hours.