I don't know where I came up with this one, but it was quite tasty. I was making cocktails for a party and wanted something that was sweet, exotic, and of course, delicious. There was an unopened 2-liter of Hawaiian punch laying about, and I went for it.
1 oz Bacardi Dragon Berry Rum
1 oz Sailor Jerry Rum (this is 90 proof, so if you use a different dark rum, try 1.5 ounces)
1 oz Sprite
1 oz Hawaiian Punch
Mix all ingredients with ice in a cocktail shaker and serve, preferably with a colorful umbrella. This is basically a martini, which I served in mini martini glasses. If you want a larger portion, increase the amount of mixers. Or not.... Enjoy!