How to speed up page load?

A very common interview question and a really good video is here:

An interesting way to look at the question:

To understand how absurd this question is – for fast pages, what is the right number of requests and optimal page size, Paul posed another similar question – for good health, what is the right number of meals and optimal pounds per meal to eat?

The answer is – not all requests are equal, not all bytes are equal.