Some fairly high speed photography was involved here to capture how a cat uses its tongue to drink.  As you can see the cat uses it backside of its tongue to cup the liquid into its mouth.

The photo was taken with a 50mm macro lens on a tripod on 1/160 @ f7.1

drinkmilk

A great example of how natures perfect design allows the most difficult of tasks to be accomplished with ease, you try drinking milk this way :-)

Remember some cats are cats lactose intolerant so go easy on the milk.