This drink is perfect for a hot summer's day.
Get an empty 2 litre bottle and fill about 1/6 with rum. Next pour in a can and a bit of Carling (or other larger), to get it to half way point. Finally, finish with 2/3 of cola and 1/3 freshly squeezed lime juice. Alternatively, the new lime cola tastes good too.
Put bottle in freezer for 2 - 6 hours, and ice forms a kind of slurry that goes down smoothly.