1.Stir sugar and the water in a small saucepan over medium heat until sugar dissolves. Bring to the boil. Reduce heat; simmer 1 minute. Cool.
2.Blend mango, sugar syrup, juice, tequila and orange flower water until smooth. Pour into a 3-litre (12-cup) shallow dish. Freeze for at least 4 hours or overnight until frozen.
3.Combine salt flakes and rind on a small plate. Run the lime wedge around the rim of 8 glasses. Dip the rim of each glass in the salt mixture.
4.Blend frozen mango mixture until smooth. Spoon into glasses.
You can also coat the rim of the glasses with a mixture of sugar and lime rind, if you prefer. You will need about 2 medium mangoes and 22 limes for this drink. To increase the amount of juice you get from the limes, either roll each lime on a hard surface or microwave them for 20 seconds before juicing.