from Casey:

2 cups mango (cubed and frozen)
1 cup strawberries (also frozen)
juice from 1 lime
1/2 Cup simple syrup
4 shots rum (generous pours, of course ;)

Throw everything in the blender and blend until smooth. It will be _thick_ and fills 4 cocktail glasses.

Don't have simple syrup? That's equal parts sugar and water heated until all the sugar is dissolved.

Also, my strawberries were tart, so you may hold back on the simple syrup if yours are sweet.