I don't often do that, but I completely dissagree with one of the posts here - some people assume that if you give your child what he/she wants even if they don't ask for it properly, he/she will become lazy and not talk properly.
I dissagree with that completely. Children learn to speak by imitating sounds and noises, and they get a positive response (by getting what they want). It is very frustrating for them if they don't get what they want, and it is counterproductive.
I have a two year old who has glue ear and can only say one word ('yes'). Imagine how frustrating it would be for him to try to tell me he wants milk if he can't even hear the word properly, and I wouldn't give it to him. Sometimes, glue ear can go undetected for a long time...
So let's say DS wants' milk, he takes me to the fridge and shows me what he wants. I repeat the word 'milk' a few times, and asy 'is it milk that you want? nice cold milk? Milk in your beaker? Yummy milk' mmm milk, milk!. Obviously I have to say it loudly, but repetition is much more efficient then waiting for them to say a word, then they get frustrated and cry. Refusing to give them something creates a very negative feeling towards expressing themselves.
It's not something I've read, it's just my own personal opinion.